The Heartbreak Gene
Death, Injury, and Pain on the Field
I
wasn’t there that day, February 12, 2000, in the desiccated winter air at the indoor track at Evanston Township High School. I had graduated and was off running at college. But my brother was a freshman on the team and my father was there too, videotaping. He was among the spectators in the aluminum bleachers standing up for a better look when my friend and former training partner, Kevin Richards, went down.
It was not unusual for a bone-tired runner to crumple to the ground after a hard race. But it had never happened to Kevin before. His teammates knew him to address his aches in silence, and always standing up. He embraced the pain of a race, and scorned the practice of lying down in exhaustion. “I love being sore,” he once said. “It feels like you did something.”
Normally, a fallen runner draws only slight curiosity from a track-savvy crowd. But Kevin was a state champion, and the dusty, green rubber floor of the track was no place for a state champion to be lying on his back, shuddering.
Kevin’s mother, Gwendolyn, had sensed something was wrong with him that morning when he overslept. He never overslept on race day. She thought he must be getting sick, so she asked him not to go. But Dan Glaz of Amos Alonzo Stagg High School was in town to race the mile. Glaz was one of the best runners in Illinois. He would become a state champion and earn a scholarship to Ohio State.
Kevin was a junior, and he was getting recruiting packets too. In addition to being one of the top half-milers in Illinois, Kevin was an honors student, and would be the first in his family of Jamaican immigrants to attend college. He had told me—often while I was struggling to breathe on our runs—that he wanted to be a video game designer, and Indiana University was atop his college wish list. On this day, he wasn’t about to miss a chance to run against Glaz, a potential future Big Ten rival.
Gwendolyn, who worked at a nursing home, had been reluctant to bank on Kevin’s speed, so she attended financial aid seminars to figure out how to pay for college, until Kevin told her to stop. “You aren’t paying a penny for me,” he said, and then turned his back and walked away.
Moments before he crumpled to the floor, Kevin had been flying through the final surge, in pursuit of Glaz. There were other runners in the race, but it had become a duel between Kevin and Glaz. The duo had already lapped the field. With two laps to go, Glaz opened a gap, but as the bell clanged hollowly, signaling the final lap, Kevin reached down. He came steaming back around the final curve, swallowing ground and slicing into Glaz’s lead with each gaping stride. He ran out of room, just barely, and finished on Glaz’s shoulder, in second place.
Kevin walked a few exhausted steps past the finish line. As coach David Phillips came to lend a supporting arm, Kevin slipped through his grasp to the floor and started to shake.
Bruce Romain, the head athletic trainer, had seen nearly one hundred seizures in his career. He knelt beside Kevin and took his pulse. It was racing. He squeezed Kevin’s hand. Kevin did not squeeze back, but continued, like a fish washed ashore, to quake and heave and force air out of his mouth. Bits of saliva frothed over his lower lip with each labored breath.
A fireman among the spectators called the paramedics. Within minutes of Kevin’s collapse, emergency medical technicians raced into the field house to help Romain give him mouth-to-mouth resuscitation. Kevin gave a mighty suck, and then exhaled a long, lackadaisical sigh. He stopped breathing.
Romain looked across Kevin’s body at a medic. The eyes of the two professional rescuers locked. “Oh, shit,” Romain blurted, as Kevin’s pulse disappeared. A medic rushed back to the rig for defibrillator paddles. Romain and the other medic continued furiously to give Kevin CPR. One of them acted as Kevin’s lungs, blowing oxygen-rich air into his mouth. The other was his heart, pushing down on his chest to force the oxygenated blood to flow through his body. But CPR could only buy some time. It could not make Kevin’s heart beat again. Like a car in need of a jump start, only a machine could save him now.
Somewhere on that last lap, the electrical signals that cued Kevin’s heart to pump had begun to misfire horribly. Rather than contracting and relaxing rhythmically, Kevin’s heart trembled, like Jell-O on a shaken tray. His left ventricle, the chamber that takes oxygenated blood from the lungs and squeezes forcefully, sending it hurtling through the body, had malfunctioned, causing a circulatory traffic jam. Blood backed up in the capillaries in his lungs—vessels so narrow that red blood cells have to move through them in single file—while the water in Kevin’s bloodstream pushed through the capillary walls and seeped into the tiny air sacs in his lungs. Water occupied the space where oxygen should have been. Kevin began drowning in his own body’s water.
The medic returned with the defibrillator paddles. They would try to jolt Kevin’s heart back into a normal rhythm by jarring it with electricity. They meant to shock him back to life, and they hoped they could do it sooner rather than later. Of all the times Kevin had been measured by the clock, these next few minutes on the track would be the most critical of his life. In the time it took him to run a mile, Kevin’s brain cells would begin to die in droves, in the poisonous, oxygenless environment of his own head.
One of Kevin’s teammates paced back and forth near the finish line murmuring, “No way. He’s too strong.” Romain backed away, stunned. He told one of the assistant coaches to call Gwendolyn at her work. By the time she arrived, her son was being loaded into an ambulance. She forced her way into the passenger seat. A medic pulled down a shade so she could not see her son being worked on in the back.
When they arrived at Evanston Hospital, Gwendolyn sat in the waiting room, passing the longest minutes of her life. Then a chaplain came to meet her. “I know he’s dead! Just tell me he’s dead!” she screamed. Then she fainted.
Kevin was dead. He had died at the track.
•
Somewhere amid the three billion base pairs—the chemical compounds that form the rungs of the twisting DNA ladder—Kevin had a single misspelling in his genetic code. That’s like a single typo in a string of letters vast enough to fill thirteen complete sets of the Encyclopaedia Britannica.
Kevin’s genetic mutation could have been in any one of billions of locations. One particular spot would have caused him to have muscular dystrophy, while another would have left him colorblind. Many, many other locations would have had no discernible impact at all, as is the case with most of the mutations that each one of us carries around every day. But Kevin’s mutation occurred at the precise rung of the DNA ladder to draft the biological blueprint for a broken heart.
Kevin had hypertrophic cardiomyopathy, or HCM, a genetic disease that causes the walls of the left ventricle to thicken, such that it does not relax completely between beats and can impede blood flow into the heart itself. About one in every five hundred Americans has HCM, though many will never exhibit serious symptoms. According to Barry Maron, director of the Hypertrophic Cardiomyopathy Center at the Minneapolis Heart Institute Foundation, HCM is the most common cause of natural sudden death in young people. And it’s easily the most common cause of sudden death in young athletes.
According to statistics that Maron has compiled, at least one high school, college, or pro athlete with HCM will drop dead somewhere in the United States every other week. Some of them will be famous, like Atlanta Hawks center Jason Collier, or San Francisco 49ers offensive lineman Thomas Herrion, or Cameroonian soccer pro Marc-Vivien Foé. Most, though, will be like Kevin Richards—teenagers, just on the verge of becoming.
In those people, the muscle cells of the left ventricle are not stacked neatly like bricks in a wall, as they should be, but are all askew, as if the bricks had instead been dumped in a pile. When the electrical signal that cues the heart to flex travels across the cells, it is liable to bounce around erratically. Intense athletic activity can trigger this short-circuit, which is especially dangerous during competition, when an athlete straining his body will not respond to the early signs of danger.
For the nation’s most pressing health problems—diabetes, hypertension, coronary artery disease—exercise is a miraculous medicine. But people with HCM can be at increased risk of dropping dead precisely because they exercise.
Eileen Kogut, for example, had long known that something dangerous ran in her family. When Kogut was twenty-one, in 1978, her fifteen-year-old brother, Joe, was playfully roughhousing with their brother Mark at the dinner table when Joe dropped dead. The autopsy report listed the cause of death as “idiopathic hypertrophic subaortic stenosis”—essentially, a heart that is enlarged for unknown reasons. “Joe was the youngest of seven siblings,” Eileen says. “His death was incredibly devastating to our family.” So Mark, who carried the memory of his little brother dying right in front of him, started working out every day, just in case he had a faulty heart, like Joe. Mark was on a treadmill at the YMCA in Lansdowne, Pennsylvania, in 1998, when he collapsed and died. The cause of death, again: an enlarged heart of unknown cause. Mark was thirty-seven. He left behind a wife and three young sons.
HCM is passed down in what’s called “autosomal dominant” fashion, which simply means that there is a 50-50 chance—a coin flip—that a parent with the culprit gene will pass it to a child.
Eileen Kogut eventually learned that HCM was what took her brothers, and in 2008 she decided to look into her own DNA.
•
Just across the Charles River from Boston’s Fenway Park is another structure of brick and steel. But rather than flags commemorating World Series wins, snaking down three stories of the exterior of this building are two winding metal ribbons, an artistic depiction of the DNA double helix.
Inside the building—the Harvard-affiliated Partners HealthCare Center for Personalized Genetic Medicine—geneticist Heidi Rehm directs the Laboratory for Molecular Medicine. Rehm and her lab staff identify new HCM mutations by the week. In the early 1990s, it was thought that HCM came from any one of seven different mutations on a single gene, the MYH7 gene, which codes for a protein found in heart muscle. By the time I visited Rehm’s lab in 2012, there was a database that included 18 different genes and 1,452 different mutations (and counting), any one of which can cause HCM. Most of the mutations are in genes that code for proteins found in heart muscle, and around 70 percent of people with HCM have a mutation on just one of two specific genes. (To make matters extremely complicated, though, two thirds of the different HCM mutations are “private mutations.” That is, each one has only been identified in a single family.) The most common cause of HCM is a DNA spelling error known as a “missense” mutation. A missense mutation occurs when a single letter is swapped in the DNA code, but in such an important place that it changes the amino acid that goes into making the resulting protein.
HCM mutations can occur randomly in someone with no family history of the disease, but most HCM gene variants are passed from parents to children. Some, however, don’t make it down family lines. One particularly dangerous HCM gene variant only ever appears as a spontaneous mutation in a single individual in a family. “That’s because it’s reproductive lethal,” Rehm says. “No one ever survives to an age to reproduce and pass it on.”
Other mutations can be so mild as to go entirely unnoticed over a lifetime, like the “Trp-792 frameshift,” which sounds like it’s out of an NFL playbook, but is actually a mutation found specifically in Mennonite people.
In most instances, though, it’s difficult to tell whether a particular mutation puts an HCM patient at risk of sudden death. In Kevin’s case, the disease was only diagnosed after he died and his heart was examined. Kevin’s autopsy showed that his heart was a gargantuan 554 grams. An average adult male heart is around 300 grams. Kevin had no obvious signs of disease, other than that he had once been told he had a heart murmur. But so had I, and so have hordes of athletes who have been at the flat end of a stethoscope. As with any muscle, the heart gets stronger with exercise, and athletes often have nondangerous heart murmurs that go away when they’re out of shape.*
Given her family history, Eileen Kogut had all her children’s hearts checked regularly from the time they were little. Her son Jimmy, who played basketball and lifted weights, had occasionally complained of shortness of breath. He was told he had asthma, a common but dangerous misdiagnosis for someone with HCM, because asthma inhalers can prompt lethal heart rhythms in HCM patients. In 2007, as he was getting set to start junior year at the University of Pittsburgh, Jimmy had a genetic test and learned that he has one of the most common HCM mutations, on a gene that helps to regulate heart contraction. Like his hazel eyes and freckles, he got it from Eileen. With the family mutation identified, Eileen decided to have her other children, Kyle, then eighteen, Connor, then sixteen, and Kathleen, then twelve, tested, even though they weren’t showing symptoms. In March 2008, she took the kids for genetic screening and prayed that she hadn’t passed the mutation to any more of her children.
But the tidings were bad. Connor and Kathleen both came up positive. “I was devastated,” Eileen says. “I don’t know what I expected. I expected to hear good news. It was not an easy pill to swallow . . . I was angry at the lab. I was not coping well. I just thought, ‘Why did I ever do this? They’re young, what was I thinking? It’s going to ruin their childhood.’”
Cardiologists who study HCM recommend that people with the disease abstain from extremely rigorous activity, because the increase in adrenaline may spark a deadly heart rhythm. After the diagnosis, Jimmy underwent surgery to have a defibrillator implanted in his chest. About the size of a matchbox, the tiny device has wires that reach into the heart and stand guard, waiting for an abnormal heart rhythm. If one is detected, the defibrillator automatically fires an electrical shock to jolt the heart back to a normal pattern. Jimmy returned to college life as usual, minus the basketball. And weight lifting was restricted to nothing overhead or that could stress his left side so much that it might damage the defibrillator wires.
Ultimately, Eileen overcame her dismay and is glad she had her children tested, even though it meant certain lifestyle changes. As she had learned in the cruelest way, the only outcome worse than losing one brother is losing two. And the only fate worse than that would be losing two brothers and a child. Says Rehm, “I got totally hooked on this area of genetics because it really is an area where you can make a difference in patients’ lives—to be able to figure out the cause of their HCM, and predict it in other family members. Sometimes you get bad outcomes, sometimes you get good outcomes, but at least you can understand it and predict it.”
A definitive determination of HCM is particularly important in athletes, because the most conspicuous sign of HCM is an enlarged heart, which is normal for athletes. It often takes a true HCM expert—of which there are precious few in the world—to tell whether the enlargement is the result of the athlete’s training or a sign of HCM. Martin Maron, Barry Maron’s son, a cardiologist at Tufts Medical Center in Boston and an expert on sudden death in athletes, says that the specific enlargement depends on the sport the athlete plays. Cyclists and rowers, for example, have enlargements in the heart chambers and walls from their training, whereas weight lifters have thicker walls but not chambers. Each sport has its signature pattern.
In a normal heart, the wall that divides the heart chambers is usually thinner than 1.2 centimeters, and the left ventricle chamber is typically smaller than 5.5 centimeters across. If either the wall or chamber is greatly enlarged, it’s a sign of disease. But if there is only some enlargement—a wall between 1.3 and 1.5 centimeters, and a chamber between 5.5 and 7 centimeters—then “that’s a gray zone for athletes,” Maron says. That is, the enlargement could be due either to training or to disease, and some athletes who are in the gray zone are cleared to play sports on the assumption that their large hearts are a training adaptation, only to then drop dead on the field. If, instead, the athlete is genetically tested and revealed to have a known mutation for HCM, no more gray zone.
This is one area where personalized genetic testing is making an impact on athletes in the present day—although they aren’t always eager to take advantage of it.
In 2005, center Eddy Curry was leading the Chicago Bulls in scoring when he was sidelined with an irregular heartbeat. Curry missed the end of the season and the entire playoffs while he was being evaluated.
At the suggestion of Barry Maron, the Bulls—hoping to avoid a situation where Curry might die in front of television cameras, as the NCAA’s reigning scoring and rebounding leader Hank Gathers did during a game in 1990—added a genetic testing clause to the $5 million contract offer that was on the table for Curry. If a test showed that Curry had a known HCM gene variant, the Bulls would not allow Curry to play, but would pay him $400,000 per year for the next fifty years. Curry refused the test, and the Bulls subsequently traded him to the Knicks. “As far as DNA testing, we’re just at the beginning of that universe,” Curry’s attorney, Alan Milstein, told the Associated Press. “Pretty soon, though, we’ll know whether someone is predisposed to cancer, alcoholism, obesity, baldness and who knows what else . . . Hand that information to an employer and imagine the implications.”
Today, the situation would be different. After thirteen years of haggling over genetic privacy, the U.S. Congress passed into law the Genetic Information Nondiscrimination Act of 2008, or GINA. The law took effect in late 2009, and barred employers from demanding genetic information, and both employers and health insurance companies from discriminating based on genetic information. (GINA does not, however, prohibit discrimination by providers of life, disability, and long-term care insurance.)
Plenty of athletes, even knowing they carry a dangerous mutation, choose to continue playing. In a 2009 moment immortalized on YouTube, Anthony Van Loo, then a twenty-year-old defender on the Belgian soccer team SV Roeselare, crumpled to the pitch like a marionette whose strings had been cut. Van Loo was in cardiac arrest. Seconds later, he jerked violently and then sat up, as if nothing had happened. Van Loo’s implanted defibrillator had fired and literally yanked him back from death’s door. He was lucky, as implantable defibrillators aren’t built to withstand the wear and tear of vigorous sports.
Whether to let an athlete with HCM participate in sports is a dilemma for doctors, who are frequently left guessing if their particular HCM patient is one of those who is at risk of sudden death, or one of those who will live to ninety with no serious symptoms.
Certain HCM mutations are known to be more dangerous than others, but it’s an inexact science. “I see some kids, and they don’t have a family history of death and they don’t have symptoms or a very thick heart, and I don’t think a lot of them are at great risk,” says Paul D. Thompson, a cardiologist at Hartford Hospital and a competitor in the 1972 U.S. Olympic marathon trials. “I usually say to them, ‘I don’t think you’re at great risk, but I have to sleep at night, and I can’t take a chance with you, so I’m prohibiting you.’ For some acne-stained seventeen-year-old who’s accepted at that high school because he’s a good linebacker, to tell him that’s gone is a load.”
It’s better, though, than the linebacker himself being gone. When I went home for my friend Kevin’s funeral, I visited the indoor track where he died. One of the white lines that demarcates a track lane was covered in penned messages: “LUV YA 4 LIFE”; “HOPE TO SEE YOU ON THE OTHER SIDE”; “WHEN THE TIME COME, YOU GOING TO LET US ALL KNOW WHY YOU DIED.” When I visited again, a year later, the messages were there, in the floor with Kevin’s sweat and dreams, but they were invisible beneath a fresh coat of paint.
•
Kevin never knew he had a time bomb inside his chest. But what if he had? At his funeral, friends emphasized that he died doing what he loved. Kevin did love to race. But he loved other things too, like computers. Racing might have been his scholarship ticket, but I have no doubt that he would have stopped running and eagerly rechanneled his competitive energy elsewhere. For me, there is scant solace in the poetic detail that he died running.
While the issue of whether to preemptively restrict an athlete is beset with emotional and legal barbs, cardiologists agree that when an athlete is clearly at risk of dropping dead on the field, the recommendation should be to avoid the field. (Though some athletes ignore the advice and play anyway.) But what if the athlete was just at risk of damage? Sports are inherently risky. Like flying fighter jets, no one participates for too long without an injury. But what if scientists could tell that some athletes are at greater risk than others?
Right now, they are beginning to be able to do just that, as researchers probe genes associated with some of the most high-profile medical risks in all of sports.
•
On a brisk November afternoon in Manhattan, Ron Duguay had just finished several hours of cognitive testing when he settled into a chair overlooking Park Avenue South to await news from Dr. Eric Braverman. Beginning in 1977, Duguay played twelve seasons in the NHL, primarily as a center with the New York Rangers. Duguay was a good player—he made the ’82 All-Star Game—but was better known as hockey’s rock star.
Duguay didn’t wear a helmet, and the curly brunette locks that fluttered behind him when he skated made him a sex symbol in the 1980s. Even today, in his fifties and married to erstwhile supermodel Kim Alexis, Duguay’s hair is thick and curly, and he is friendly and easy to talk to. In Braverman’s office, though, he’s nervous. He fiddles with his gleaming Rangers pinkie ring when he mentions that friends often tell him he should write a book about his hockey days. “I’d have to call up my teammates,” he says. “There’s a lot I can’t remember.” That’s why Duguay is here. He thinks he suffered undiagnosed concussions during his career, and he knows he took scores of lesser hits to the head from sticks, elbows, and the occasional puck.
Braverman appears and flatly tells Duguay that he flunked three of the tests meant to gauge his memory and brain processing speed. “He’s a mess compared to his old self,” Braverman says.
As part of the testing, Braverman also ordered a genetic test to see what versions Duguay has of a gene known as apolipoprotein E, or ApoE. Duguay’s grandmother died from Alzheimer’s disease, and another family member has been having memory problems. Studies of Alzheimer’s patients indicate that a particular version of the ApoE gene substantially increases an individual’s risk of getting the disease.
The gene comes in three common variants: ApoE2, ApoE3, and ApoE4. Everyone has two copies of the ApoE gene, one from Mom and one from Dad, and a single ApoE4 copy increases the risk of Alzheimer’s threefold. Two copies increases the risk eightfold. Around half of Alzheimer’s patients have an ApoE4 gene—compared with a quarter of the general population—and those who do tend to develop the disease at a younger age.
The importance of the ApoE gene extends beyond Alzheimer’s to how well an individual can recover from any type of brain injury. Carriers of ApoE4 gene variants who hit their heads in car accidents, for example, have longer comas, more bleeding and bruising in the brain, more postinjury seizures, less success with rehabilitation, and are more likely to suffer permanent damage or to die.
It is not entirely understood how ApoE influences brain recovery, but the gene is involved in the brain’s inflammatory response following head trauma, and people who have an ApoE4 variant take longer to clear their brains of a protein called amyloid, which floods in when the brain is injured. Several studies have found that athletes with ApoE4 variants who get hit in the head take longer to recover and are at greater risk of suffering dementia later in life.
A 1997 study determined that boxers with an ApoE4 copy scored worse on tests of brain impairment than boxers with similar length careers who did not have an ApoE4 copy. Three boxers in the study had severe brain function impairment, and all three had an ApoE4 gene variant. In 2000, a study of fifty-three active pro football players concluded that three factors caused certain players to score lower than their peers on tests of brain function: 1) age, 2) having been hit in the head often, and 3) having an ApoE4 variant.
In 2002, at age forty, former Houston Oilers and Miami Dolphins linebacker John Grimsley began to show signs of dementia. His family noticed that he would repeat the same question, that he could not remember what groceries to buy without a list, and that he would ask to rent movies he had already seen.
Though an experienced hunting guide, Grimsley accidentally shot and killed himself in 2008 while cleaning one of his guns. Grimsley’s wife, Virginia, had long wondered whether the concussions her husband suffered had anything to do with his mental deterioration, so she donated his brain to Boston University’s Center for the Study of Traumatic Encephalopathy.
It was the first of many brains belonging to former NFL players that the BU researchers would examine en route to increasing awareness of the danger of brain trauma in sports. The researchers at the center found an extensive buildup of protein in Grimsley’s brain, characteristic of chronic traumatic encephalopathy, or CTE. The condition has now been found in scores of brains from college and pro football players. The BU scientists also found that Grimsley—like just 2 percent of the population—had two copies of the ApoE4 gene variant.
In 2009, the BU researchers made national headlines (and headaches for the NFL) when they reported on dozens of cases of brain damage in boxers and football players. What went entirely unmentioned in media coverage, though, was that five of nine brain-damaged boxers and football players who had genetic data included in the report had an ApoE4 variant. That’s 56 percent, between double and triple the proportion in the general population. Brandon Colby, a Los Angeles–based physician who treats former NFL players says of those patients: “Of the ones who have noticeable issues from head trauma, every single one had an ApoE4 copy.” Colby now offers ApoE testing of children to parents who want to weigh the risks of playing football.
Neurologist Barry Jordan, coauthor of the 2000 study of fifty-three football players, and former chief medical officer of the New York State Athletic Commission, once considered making genetic screening for the ApoE4 variant mandatory for all boxers in New York. “I don’t think you can stop an athlete from participating,” Jordan says, “but it might help just in monitoring them closely. [An ApoE4 gene variant] doesn’t seem to increase the risk of concussion, and I wouldn’t expect it to, but it may affect your recovery following concussion.”
Ultimately, Jordan decided not to implement mandatory genetic testing, primarily because he was concerned about how the information could be used. “Even with [the Genetic Information Nondiscrimination Act],” Jordan says, “you never know. Information still gets out. I think genetic testing is something you can educate athletes about. But I’m not sure how interested people would be in it. Some people don’t want to know.” Or, as James P. Kelly, a neurologist who was on the Colorado State Boxing Commission, put it: “With ApoE4, some would argue that knowledge is not power.”
It’s fraught territory, but most current or former pro athletes to whom I explained an ApoE4 test seemed eager to take one, provided the information would be kept from teams, insurance companies, and potential future employers.* Weeks after his visit to Dr. Braverman, Ron Duguay learned that he did indeed have an ApoE4 variant. Had he known of this potential additional risk factor for cognitive impairment, Duguay says he “would’ve seriously considered wearing a helmet” during his playing days.
Among other athletes I asked about their interest in ApoE testing was Glen Johnson, a professional boxer with seventy-one fights, including wins in 2004 over Roy Jones Jr. and Antonio Tarver. Johnson knew that getting hit in the head—and not simply a particular gene—was the primary factor for brain damage, but says, “I’d never hide from extra information.”
Former New England Patriots linebacker Ted Johnson, who suffered a series of concussions that led him to retire and later suffered from amphetamine addiction, depression, memory problems, and chronic headaches, says: “I would be the first person signed up for a test. I wouldn’t even hesitate. I know it’s no guarantee just because you have this gene, but if it’s true that you are potentially at greater risk than the average person, I would do it in a heartbeat. When I was playing we had no information. . . . This kind of information would be incredible to have if you’re a current player.” One Alzheimer’s researcher at Mount Sinai Hospital in New York has noted that the dementia risk of having a single ApoE4 copy is roughly similar to the risk from playing in the NFL, and that the two together are even more dangerous.
But because the precise degree of additional risk is impossible to quantify, doctors I spoke with almost uniformly felt that ApoE testing should not be offered to athletes. “This is a very controversial area,” says Robert C. Green, a BU neurologist who collaborated on the REVEAL Study, which examined how people who volunteer for ApoE screening react when they get bad news. “The world of genetics for decades has suggested that there’s no reason to give people genetic-risk information unless there’s something proven you can do about it.” REVEAL found, though, that people who learned they had an ApoE4 variant did not experience undue dread. Rather, study subjects who got bad news tended to increase healthy lifestyle habits like exercise, which doctors told them might help, even though there is no proven remedy for delaying the onset of Alzheimer’s.
Still, the doctors’ hesitation is understandable. “If we have a gene we know increases your risk of blowing out your knee, if that got into the wrong hands, somebody could decide not to sign a player,” says Barry Jordan, the former New York athletic commission medical officer. “That would be a potential problem.” (Of course, teams already go to great lengths to guess that same information using physical examinations and medical histories.)
Actually, genes have been identified that appear to alter one’s risk of blowing out a knee. Biologists at South Africa’s University of Cape Town have been leading the way in identifying genes that predispose exercisers to injuring tendons and ligaments. The researchers focused on genes like COL1A1 and COL5A1 that code for the proteins that make up collagen fibrils, the basic building blocks of tendons, ligaments, and skin. Collagen is sometimes referred to as the body’s glue, holding connective tissues in proper form.
People with a certain mutation in the COL1A1 gene have brittle bone disease and suffer fractures easily. A particular mutation in the COL5A1 gene causes Ehlers-Danlos syndrome, which confers hyperflexibility. “Those people in the old days of the circus who used to fold themselves into a box, I bet you in most cases they had Ehlers-Danlos syndrome,” says Malcolm Collins, one of the Cape Town biologists and a leader in the study of collagen genes. “They could twist their bodies into positions that you and I can’t because they’ve got very abnormal collagen fibrils.”
Ehlers-Danlos syndrome is rare, but Collins and colleagues have demonstrated that much more common variations in collagen genes influence both flexibility and an individual’s risk of injuries to the connective tissues, like Achilles tendon rupture.* Using that research, the company Gknowmix offers collagen gene tests that doctors can order for patients.
“All we can say to an athlete with a particular genetic profile is that you are at increased risk of injury based on our current knowledge,” Collins says. “It’s no different than saying that smoking a cigarette increases your chance of lung cancer. The difference is that you can stop smoking, but you can’t change your DNA. But there are other factors which you can change. You can modify whatever training you’re doing to reduce risk, or you can do ‘prehabilitation’ training to strengthen the area that is at risk.”
A gaggle of NFL players have already availed themselves of testing for “injury genes” that may predispose them to Achilles tendon injuries or torn ACLs in the knee. Duke University’s football team, as just one example, sought university approval to submit players’ DNA to a researcher on campus who would look for genes that predispose players to tendon and ligament injuries.
So specific genes have now been implicated in sudden death, brain damage, and injury on the field. And now researchers have begun to identify genes that undergird another unpleasant and unavoidable aspects of sports: pain. Genes, it seems, influence our very perception of it.
•
In the waning years of a career that spanned thirteen NFL seasons, 3,479 carries, a bevy of broken ribs, several separated shoulders, a couple of concussions, a torn groin muscle, a bruised sternum, and a legion of knee and ankle surgeries, 255-pound running back Jerome Bettis developed a Monday-morning tradition. He would sit at the top of his staircase and scoot down toward breakfast on his butt, one step at a time.
On Sundays, the Steelers expected Bettis to run through people. “That was my skill set,” he says. “It wasn’t like I could run away from them.” In one game against the Jacksonville Jaguars, a defensive player’s thumb came through Bettis’s face mask and broke his nose. Team doctors taped the nose and stuffed it with cotton. That helped, until a head-on collision late in the game propelled the cotton up through his nasal passage, down his throat, and into his stomach. “It was like, ‘Guys, wait a second, the padding is gone,’” Bettis says. “It was the worst.”
No wonder Bettis was unable to walk down the stairs on Monday mornings. The pain was so intense at times that he figured he would have to miss the next game. But once he stepped on the turf Sunday, he never backed down. “When you get on the field, it’s not even a question mark,” Bettis says. “You do your job, by any means necessary.”
Bettis was renowned for his toughness, but he says there are athletes, even in the NFL, who struggle to manage discomfort. “I think some people’s bodies kind of shut down from the pain, and it doesn’t allow them to still have peak performances,” Bettis says. “I saw that problem at times.”
Pain tolerance and pain management are as central to most high-level sports as running and jumping, and just why some people tolerate pain better than others is a topic of research at the Pain Genetics Lab at McGill University in Montreal. One room in the lab is stacked from floor to ceiling with clear tanks that house mice, all bred for the study of genes that influence how they (and humans) experience pain, and how that pain can be ameliorated.
In one tank are mice missing oxytocin receptors. They are used in the study of pain, but the mice also have deficits in social recognition. Put them with mice they grew up with and they won’t recognize them. In another corner is a tank of raven-haired mice that were bred to be prone to head pain, that is, migraines. They spend a lot of time scratching their foreheads and shuddering, and they are apparently justified in using the old headache excuse to avoid mating. “This experiment has taken years,” says Jeffrey Mogil, head of the lab, of the work that seeks to help develop migraine treatments, “because they breed really, really badly.”
On another shelf is a tank of mice with nonfunctioning versions of the melanocortin 1 receptor gene, or MC1R. In plain language, they’re redheads. It’s the same gene mutation that is responsible for the ginger locks of most human redheads. Mogil found that both people and rodents with the redhead mutation have higher tolerance for certain types of pain, and require less morphine for relief.
MC1R was among the first genes identified that influence how humans experience pain. Another was discovered by scientists who followed the theatrical talents of a ten-year-old Pakistani street performer.
Medical workers in Lahore knew the boy well, because after he stuck knives through his arms and stood on burning coals he would come in to get stitched back together. But they never treated him for pain. The boy could feel no pain.
By the time British geneticists traveled to Pakistan to study him, the boy had died, at the age of fourteen, after jumping off a roof to impress his friends. But the scientists found the same condition in six of the boy’s extended relatives. “None knew what pain felt like,” the scientists wrote, “although the older individuals realized what actions should elicit pain (including acting as if in pain after football tackles).”
The “older individuals” were just ten, twelve, and fourteen. People born with congenital insensitivity to pain tend not to live very long. They don’t shift their weight when sitting, sleeping, or standing as the rest of us do instinctively, and they die from the joint infections that result.
Each of the Pakistani relatives with pain immunity had a very rare mutation in the SCN9A gene. The mutation blocked pain signals that normally travel from nerves to the brain. A different mutation in SCN9A causes those who carry it to be hypersensitive to pain, bothered by warmth so easily that they won’t wear shoes. In 2010, the British geneticists teamed up with researchers in the United States, Finland, and the Netherlands for a study that reported that much more common variations in SCN9A influence how sensitive adults are to common types of pain, like back trouble. Genetic variation among individuals, it seems, ensures that none of us can truly know another’s physical pain.
The gene that has been most studied for its involvement in pain modulation is the COMT gene, which is involved in the metabolism of neurotransmitters in the brain, including dopamine. Two common versions of COMT are known as “Val” and “Met,” based on whether a specific part of the gene’s DNA sequence codes for the amino acid valine or methionine.
In both mice and humans, the Met version is less effective at clearing dopamine, which leaves higher levels in the frontal cortex. Cognitive testing and brain imaging studies have found that subjects with two Met versions—both animals and humans—tend to do better on and require less metabolic effort for cognitive and memory tasks, but that they are also more prone to anxiety and more sensitive to pain. (Anxiety, or “catastrophizing,” is a strong predictor of an individual’s pain sensitivity.) Conversely, Val/Val carriers seem to do slightly worse on cognitive tests that require rapid mental flexibility, but may be more resilient to stress and pain. (They also get a better boost from Ritalin, which increases dopamine in the frontal cortex.) Additionally, COMT is involved in metabolism of norepinephrine, which is released in response to stress and has a protective effect.
David Goldman, chief of the Laboratory of Neurogenetics at the NIH’s National Institute on Alcohol Abuse and Alcoholism, coined the phrase “warrior/worrier gene” to describe the apparent tradeoffs of the two COMT variants. Both versions are common everywhere in the world they’ve been studied. In the United States, Goldman says, 16 percent of people are Met/Met; 48 percent are Met/Val; and 36 percent are Val/Val, leading him to suggest that both warriors and worriers are needed in every society, so there is widespread preservation of both forms of the gene. “We’ve never done the study,” Goldman says, “but I predict if I took a big group of NFL linemen that they would tend to have the Val genotype, because they’re in the trenches every day and they’re exposed to pain and they just have to have this super resilience and toughness.” *
In fairness, studies of the COMT gene have often been contradictory, and the gene’s relevance to pain sensitivity is hotly debated among pain researchers. But the idea that genes involved in emotional regulation might alter pain sensation is uncontroversial. Morphine, after all, doesn’t so much decrease pain intensity, but rather reduces the emotional unpleasantness that results from pain. “The pain circuitry is shared so strongly with the circuitry of emotion,” Goldman says, “and many of the neurotransmitters are too. As you modify emotion, you strongly modify pain response.”
And sports can be strong modifiers.
•
Haverford College psychologist Wendy Sternberg was giving a lecture on stress-induced analgesia—the brain’s ability to block pain in high-pressure situations—when a student told her that it sounded just like what happens to athletes in competition.
A 2004 Ultimate Fighting Championship heavyweight title fight is an excruciating example. Brazilian jiu-jitsu black belt Frank Mir caught 6'8" Tim “The Maine-iac” Sylvia in a joint lock called an armbar. Mir grabbed Sylvia’s extended right arm, braced the elbow joint against his hip, and pulled backward so forcefully it looked as if he were heaving back a train brake.
The pop of Sylvia’s shattering arm was audible on television. Referee Herb Dean rushed in to separate the fighters and shouted for the match to stop. Sylvia set to cursing and demanding that the fight continue. Only later, as he sat on a gurney en route to the hospital, did Sylvia begin to feel pain and realize that his attempt to keep fighting had been ill considered. It took three titanium plates to rig his arm back together. “[The ref] probably saved my career,” Sylvia says, because in the heat of battle he couldn’t perceive the pain on his own.
Says Sternberg, “Under conditions of acute stress the brain inhibits pain, so you can fight or flee without worrying about a broken bone.” A system to block pain in extreme situations evolved in the genes of all humans, and even quotidian sports settings tap into it.
In 1998, prompted by her student’s suggestion, Sternberg tested the sensitivity of Haverford track athletes, fencers, and basketball players to cold and heat pain two days before they competed, on the day of a competition, and two days later. She found that basketball players and runners were less sensitive to pain than their nonathlete peers to begin with, and that all of the athletes were least sensitive to pain on game day. “I think athletic competition can activate the fight-or-flight mechanism,” Sternberg says. “When you get in a competition that you care about, you’re going to activate it.”
•
Pain can be modified by a game situation or by the emotions of an athlete, but the genetic blueprint for pain in the body is encoded in the brain, whether or not that body even exists in its entirety. (People who are born without limbs or who have them amputated nonetheless often experience pain in those “phantom limbs.”) Still, pain must be practiced in the first place.
In the 1950s, Canadian psychologist Ronald Melzack was working toward his Ph.D. at McGill under psychologist D. O. Hebb, who was studying how extreme deprivation of life experience affects intellect. Hebb was experimenting on Scottish terriers.
The dogs were well cared for, groomed, and fed, but they were totally isolated from the outside world. Hebb was interested in how that would alter their ability to navigate a maze. (The answer: very negatively.) But it was in the holding room, before the maze, where Melzack made the observation that started him down the road to becoming the most influential pain researcher in the world. “The water pipes in the room were at head level for the dogs,” Melzack says, “and these wonderful dogs would run around and bang their heads right into the pipes, as if they felt nothing. And they kept running around and banging their heads on the water pipes.”
Melzack was a smoker at the time, so he struck a match. “I held it out, and they’d put their nose in it,” he says. They’d back up, “and then come back and sniff it again. I’d put it out and light another match, and they’d sniff it again and again.” The dogs obviously had normal cerebral hardware, but had missed the critical developmental window for downloading the brain’s pain software. They never learned to be deterred by the flame. Just like language, or hitting a baseball, even though each of us may be born with the requisite genetic hardware, if we miss the window for acquiring the software, the genes are of little use. Adds Jeffrey Mogil, of McGill’s Pain Genetics Lab: “The fact that something like pain would have to be learned at all is pretty surprising.”
•
Pain is innate, but it also must be learned. It is unavoidable, and yet modifiable. It is common to all people and all athletes but never experienced quite the same way by any two individuals or even by the same individual in two different situations. Each of us is like the hero in a Greek tragedy, circumscribed by nature, but left to alter our fate within the boundaries. “Maybe if you’re a worrier by genotype, it’s a better idea not to be a warrior by profession,” says Goldman, the neurogeneticist. “Then again, it’s hard to say, because people overcome so much.”
Like most traits discussed in this book, an athlete’s ability to deal with pain is a braid of nature and nurture so intricately and thoroughly intertwined as to become a single vine. As one scientist told me: without both genes and environments, there are no outcomes.
It reinforces the idea that any notion of finding an “athlete gene” was a figment of the era of wishful thinking that crested a decade ago with the first full sequencing of the human genome, before scientists understood how much they don’t understand about the complexity of the genetic recipe book. What, exactly, most human genes do is still a mystery. Sure, the ACTN3 gene may tell a billion or so people in the world that they won’t be in the Olympic 100-meter final, but chances are they all already knew that.
If thousands of DNA variations are needed to explain just a portion of the differences in height among people, what are the chances of ever finding a single gene that makes a star athlete? Slim? Or none?
And yet . . .
Death, Injury, and Pain on the Field
I
wasn’t there that day, February 12, 2000, in the desiccated winter air at the indoor track at Evanston Township High School. I had graduated and was off running at college. But my brother was a freshman on the team and my father was there too, videotaping. He was among the spectators in the aluminum bleachers standing up for a better look when my friend and former training partner, Kevin Richards, went down.
It was not unusual for a bone-tired runner to crumple to the ground after a hard race. But it had never happened to Kevin before. His teammates knew him to address his aches in silence, and always standing up. He embraced the pain of a race, and scorned the practice of lying down in exhaustion. “I love being sore,” he once said. “It feels like you did something.”
Normally, a fallen runner draws only slight curiosity from a track-savvy crowd. But Kevin was a state champion, and the dusty, green rubber floor of the track was no place for a state champion to be lying on his back, shuddering.
Kevin’s mother, Gwendolyn, had sensed something was wrong with him that morning when he overslept. He never overslept on race day. She thought he must be getting sick, so she asked him not to go. But Dan Glaz of Amos Alonzo Stagg High School was in town to race the mile. Glaz was one of the best runners in Illinois. He would become a state champion and earn a scholarship to Ohio State.
Kevin was a junior, and he was getting recruiting packets too. In addition to being one of the top half-milers in Illinois, Kevin was an honors student, and would be the first in his family of Jamaican immigrants to attend college. He had told me—often while I was struggling to breathe on our runs—that he wanted to be a video game designer, and Indiana University was atop his college wish list. On this day, he wasn’t about to miss a chance to run against Glaz, a potential future Big Ten rival.
Gwendolyn, who worked at a nursing home, had been reluctant to bank on Kevin’s speed, so she attended financial aid seminars to figure out how to pay for college, until Kevin told her to stop. “You aren’t paying a penny for me,” he said, and then turned his back and walked away.
Moments before he crumpled to the floor, Kevin had been flying through the final surge, in pursuit of Glaz. There were other runners in the race, but it had become a duel between Kevin and Glaz. The duo had already lapped the field. With two laps to go, Glaz opened a gap, but as the bell clanged hollowly, signaling the final lap, Kevin reached down. He came steaming back around the final curve, swallowing ground and slicing into Glaz’s lead with each gaping stride. He ran out of room, just barely, and finished on Glaz’s shoulder, in second place.
Kevin walked a few exhausted steps past the finish line. As coach David Phillips came to lend a supporting arm, Kevin slipped through his grasp to the floor and started to shake.
Bruce Romain, the head athletic trainer, had seen nearly one hundred seizures in his career. He knelt beside Kevin and took his pulse. It was racing. He squeezed Kevin’s hand. Kevin did not squeeze back, but continued, like a fish washed ashore, to quake and heave and force air out of his mouth. Bits of saliva frothed over his lower lip with each labored breath.
A fireman among the spectators called the paramedics. Within minutes of Kevin’s collapse, emergency medical technicians raced into the field house to help Romain give him mouth-to-mouth resuscitation. Kevin gave a mighty suck, and then exhaled a long, lackadaisical sigh. He stopped breathing.
Romain looked across Kevin’s body at a medic. The eyes of the two professional rescuers locked. “Oh, shit,” Romain blurted, as Kevin’s pulse disappeared. A medic rushed back to the rig for defibrillator paddles. Romain and the other medic continued furiously to give Kevin CPR. One of them acted as Kevin’s lungs, blowing oxygen-rich air into his mouth. The other was his heart, pushing down on his chest to force the oxygenated blood to flow through his body. But CPR could only buy some time. It could not make Kevin’s heart beat again. Like a car in need of a jump start, only a machine could save him now.
Somewhere on that last lap, the electrical signals that cued Kevin’s heart to pump had begun to misfire horribly. Rather than contracting and relaxing rhythmically, Kevin’s heart trembled, like Jell-O on a shaken tray. His left ventricle, the chamber that takes oxygenated blood from the lungs and squeezes forcefully, sending it hurtling through the body, had malfunctioned, causing a circulatory traffic jam. Blood backed up in the capillaries in his lungs—vessels so narrow that red blood cells have to move through them in single file—while the water in Kevin’s bloodstream pushed through the capillary walls and seeped into the tiny air sacs in his lungs. Water occupied the space where oxygen should have been. Kevin began drowning in his own body’s water.
The medic returned with the defibrillator paddles. They would try to jolt Kevin’s heart back into a normal rhythm by jarring it with electricity. They meant to shock him back to life, and they hoped they could do it sooner rather than later. Of all the times Kevin had been measured by the clock, these next few minutes on the track would be the most critical of his life. In the time it took him to run a mile, Kevin’s brain cells would begin to die in droves, in the poisonous, oxygenless environment of his own head.
One of Kevin’s teammates paced back and forth near the finish line murmuring, “No way. He’s too strong.” Romain backed away, stunned. He told one of the assistant coaches to call Gwendolyn at her work. By the time she arrived, her son was being loaded into an ambulance. She forced her way into the passenger seat. A medic pulled down a shade so she could not see her son being worked on in the back.
When they arrived at Evanston Hospital, Gwendolyn sat in the waiting room, passing the longest minutes of her life. Then a chaplain came to meet her. “I know he’s dead! Just tell me he’s dead!” she screamed. Then she fainted.
Kevin was dead. He had died at the track.
•
Somewhere amid the three billion base pairs—the chemical compounds that form the rungs of the twisting DNA ladder—Kevin had a single misspelling in his genetic code. That’s like a single typo in a string of letters vast enough to fill thirteen complete sets of the Encyclopaedia Britannica.
Kevin’s genetic mutation could have been in any one of billions of locations. One particular spot would have caused him to have muscular dystrophy, while another would have left him colorblind. Many, many other locations would have had no discernible impact at all, as is the case with most of the mutations that each one of us carries around every day. But Kevin’s mutation occurred at the precise rung of the DNA ladder to draft the biological blueprint for a broken heart.
Kevin had hypertrophic cardiomyopathy, or HCM, a genetic disease that causes the walls of the left ventricle to thicken, such that it does not relax completely between beats and can impede blood flow into the heart itself. About one in every five hundred Americans has HCM, though many will never exhibit serious symptoms. According to Barry Maron, director of the Hypertrophic Cardiomyopathy Center at the Minneapolis Heart Institute Foundation, HCM is the most common cause of natural sudden death in young people. And it’s easily the most common cause of sudden death in young athletes.
According to statistics that Maron has compiled, at least one high school, college, or pro athlete with HCM will drop dead somewhere in the United States every other week. Some of them will be famous, like Atlanta Hawks center Jason Collier, or San Francisco 49ers offensive lineman Thomas Herrion, or Cameroonian soccer pro Marc-Vivien Foé. Most, though, will be like Kevin Richards—teenagers, just on the verge of becoming.
In those people, the muscle cells of the left ventricle are not stacked neatly like bricks in a wall, as they should be, but are all askew, as if the bricks had instead been dumped in a pile. When the electrical signal that cues the heart to flex travels across the cells, it is liable to bounce around erratically. Intense athletic activity can trigger this short-circuit, which is especially dangerous during competition, when an athlete straining his body will not respond to the early signs of danger.
For the nation’s most pressing health problems—diabetes, hypertension, coronary artery disease—exercise is a miraculous medicine. But people with HCM can be at increased risk of dropping dead precisely because they exercise.
Eileen Kogut, for example, had long known that something dangerous ran in her family. When Kogut was twenty-one, in 1978, her fifteen-year-old brother, Joe, was playfully roughhousing with their brother Mark at the dinner table when Joe dropped dead. The autopsy report listed the cause of death as “idiopathic hypertrophic subaortic stenosis”—essentially, a heart that is enlarged for unknown reasons. “Joe was the youngest of seven siblings,” Eileen says. “His death was incredibly devastating to our family.” So Mark, who carried the memory of his little brother dying right in front of him, started working out every day, just in case he had a faulty heart, like Joe. Mark was on a treadmill at the YMCA in Lansdowne, Pennsylvania, in 1998, when he collapsed and died. The cause of death, again: an enlarged heart of unknown cause. Mark was thirty-seven. He left behind a wife and three young sons.
HCM is passed down in what’s called “autosomal dominant” fashion, which simply means that there is a 50-50 chance—a coin flip—that a parent with the culprit gene will pass it to a child.
Eileen Kogut eventually learned that HCM was what took her brothers, and in 2008 she decided to look into her own DNA.
•
Just across the Charles River from Boston’s Fenway Park is another structure of brick and steel. But rather than flags commemorating World Series wins, snaking down three stories of the exterior of this building are two winding metal ribbons, an artistic depiction of the DNA double helix.
Inside the building—the Harvard-affiliated Partners HealthCare Center for Personalized Genetic Medicine—geneticist Heidi Rehm directs the Laboratory for Molecular Medicine. Rehm and her lab staff identify new HCM mutations by the week. In the early 1990s, it was thought that HCM came from any one of seven different mutations on a single gene, the MYH7 gene, which codes for a protein found in heart muscle. By the time I visited Rehm’s lab in 2012, there was a database that included 18 different genes and 1,452 different mutations (and counting), any one of which can cause HCM. Most of the mutations are in genes that code for proteins found in heart muscle, and around 70 percent of people with HCM have a mutation on just one of two specific genes. (To make matters extremely complicated, though, two thirds of the different HCM mutations are “private mutations.” That is, each one has only been identified in a single family.) The most common cause of HCM is a DNA spelling error known as a “missense” mutation. A missense mutation occurs when a single letter is swapped in the DNA code, but in such an important place that it changes the amino acid that goes into making the resulting protein.
HCM mutations can occur randomly in someone with no family history of the disease, but most HCM gene variants are passed from parents to children. Some, however, don’t make it down family lines. One particularly dangerous HCM gene variant only ever appears as a spontaneous mutation in a single individual in a family. “That’s because it’s reproductive lethal,” Rehm says. “No one ever survives to an age to reproduce and pass it on.”
Other mutations can be so mild as to go entirely unnoticed over a lifetime, like the “Trp-792 frameshift,” which sounds like it’s out of an NFL playbook, but is actually a mutation found specifically in Mennonite people.
In most instances, though, it’s difficult to tell whether a particular mutation puts an HCM patient at risk of sudden death. In Kevin’s case, the disease was only diagnosed after he died and his heart was examined. Kevin’s autopsy showed that his heart was a gargantuan 554 grams. An average adult male heart is around 300 grams. Kevin had no obvious signs of disease, other than that he had once been told he had a heart murmur. But so had I, and so have hordes of athletes who have been at the flat end of a stethoscope. As with any muscle, the heart gets stronger with exercise, and athletes often have nondangerous heart murmurs that go away when they’re out of shape.*
Given her family history, Eileen Kogut had all her children’s hearts checked regularly from the time they were little. Her son Jimmy, who played basketball and lifted weights, had occasionally complained of shortness of breath. He was told he had asthma, a common but dangerous misdiagnosis for someone with HCM, because asthma inhalers can prompt lethal heart rhythms in HCM patients. In 2007, as he was getting set to start junior year at the University of Pittsburgh, Jimmy had a genetic test and learned that he has one of the most common HCM mutations, on a gene that helps to regulate heart contraction. Like his hazel eyes and freckles, he got it from Eileen. With the family mutation identified, Eileen decided to have her other children, Kyle, then eighteen, Connor, then sixteen, and Kathleen, then twelve, tested, even though they weren’t showing symptoms. In March 2008, she took the kids for genetic screening and prayed that she hadn’t passed the mutation to any more of her children.
But the tidings were bad. Connor and Kathleen both came up positive. “I was devastated,” Eileen says. “I don’t know what I expected. I expected to hear good news. It was not an easy pill to swallow . . . I was angry at the lab. I was not coping well. I just thought, ‘Why did I ever do this? They’re young, what was I thinking? It’s going to ruin their childhood.’”
Cardiologists who study HCM recommend that people with the disease abstain from extremely rigorous activity, because the increase in adrenaline may spark a deadly heart rhythm. After the diagnosis, Jimmy underwent surgery to have a defibrillator implanted in his chest. About the size of a matchbox, the tiny device has wires that reach into the heart and stand guard, waiting for an abnormal heart rhythm. If one is detected, the defibrillator automatically fires an electrical shock to jolt the heart back to a normal pattern. Jimmy returned to college life as usual, minus the basketball. And weight lifting was restricted to nothing overhead or that could stress his left side so much that it might damage the defibrillator wires.
Ultimately, Eileen overcame her dismay and is glad she had her children tested, even though it meant certain lifestyle changes. As she had learned in the cruelest way, the only outcome worse than losing one brother is losing two. And the only fate worse than that would be losing two brothers and a child. Says Rehm, “I got totally hooked on this area of genetics because it really is an area where you can make a difference in patients’ lives—to be able to figure out the cause of their HCM, and predict it in other family members. Sometimes you get bad outcomes, sometimes you get good outcomes, but at least you can understand it and predict it.”
A definitive determination of HCM is particularly important in athletes, because the most conspicuous sign of HCM is an enlarged heart, which is normal for athletes. It often takes a true HCM expert—of which there are precious few in the world—to tell whether the enlargement is the result of the athlete’s training or a sign of HCM. Martin Maron, Barry Maron’s son, a cardiologist at Tufts Medical Center in Boston and an expert on sudden death in athletes, says that the specific enlargement depends on the sport the athlete plays. Cyclists and rowers, for example, have enlargements in the heart chambers and walls from their training, whereas weight lifters have thicker walls but not chambers. Each sport has its signature pattern.
In a normal heart, the wall that divides the heart chambers is usually thinner than 1.2 centimeters, and the left ventricle chamber is typically smaller than 5.5 centimeters across. If either the wall or chamber is greatly enlarged, it’s a sign of disease. But if there is only some enlargement—a wall between 1.3 and 1.5 centimeters, and a chamber between 5.5 and 7 centimeters—then “that’s a gray zone for athletes,” Maron says. That is, the enlargement could be due either to training or to disease, and some athletes who are in the gray zone are cleared to play sports on the assumption that their large hearts are a training adaptation, only to then drop dead on the field. If, instead, the athlete is genetically tested and revealed to have a known mutation for HCM, no more gray zone.
This is one area where personalized genetic testing is making an impact on athletes in the present day—although they aren’t always eager to take advantage of it.
In 2005, center Eddy Curry was leading the Chicago Bulls in scoring when he was sidelined with an irregular heartbeat. Curry missed the end of the season and the entire playoffs while he was being evaluated.
At the suggestion of Barry Maron, the Bulls—hoping to avoid a situation where Curry might die in front of television cameras, as the NCAA’s reigning scoring and rebounding leader Hank Gathers did during a game in 1990—added a genetic testing clause to the $5 million contract offer that was on the table for Curry. If a test showed that Curry had a known HCM gene variant, the Bulls would not allow Curry to play, but would pay him $400,000 per year for the next fifty years. Curry refused the test, and the Bulls subsequently traded him to the Knicks. “As far as DNA testing, we’re just at the beginning of that universe,” Curry’s attorney, Alan Milstein, told the Associated Press. “Pretty soon, though, we’ll know whether someone is predisposed to cancer, alcoholism, obesity, baldness and who knows what else . . . Hand that information to an employer and imagine the implications.”
Today, the situation would be different. After thirteen years of haggling over genetic privacy, the U.S. Congress passed into law the Genetic Information Nondiscrimination Act of 2008, or GINA. The law took effect in late 2009, and barred employers from demanding genetic information, and both employers and health insurance companies from discriminating based on genetic information. (GINA does not, however, prohibit discrimination by providers of life, disability, and long-term care insurance.)
Plenty of athletes, even knowing they carry a dangerous mutation, choose to continue playing. In a 2009 moment immortalized on YouTube, Anthony Van Loo, then a twenty-year-old defender on the Belgian soccer team SV Roeselare, crumpled to the pitch like a marionette whose strings had been cut. Van Loo was in cardiac arrest. Seconds later, he jerked violently and then sat up, as if nothing had happened. Van Loo’s implanted defibrillator had fired and literally yanked him back from death’s door. He was lucky, as implantable defibrillators aren’t built to withstand the wear and tear of vigorous sports.
Whether to let an athlete with HCM participate in sports is a dilemma for doctors, who are frequently left guessing if their particular HCM patient is one of those who is at risk of sudden death, or one of those who will live to ninety with no serious symptoms.
Certain HCM mutations are known to be more dangerous than others, but it’s an inexact science. “I see some kids, and they don’t have a family history of death and they don’t have symptoms or a very thick heart, and I don’t think a lot of them are at great risk,” says Paul D. Thompson, a cardiologist at Hartford Hospital and a competitor in the 1972 U.S. Olympic marathon trials. “I usually say to them, ‘I don’t think you’re at great risk, but I have to sleep at night, and I can’t take a chance with you, so I’m prohibiting you.’ For some acne-stained seventeen-year-old who’s accepted at that high school because he’s a good linebacker, to tell him that’s gone is a load.”
It’s better, though, than the linebacker himself being gone. When I went home for my friend Kevin’s funeral, I visited the indoor track where he died. One of the white lines that demarcates a track lane was covered in penned messages: “LUV YA 4 LIFE”; “HOPE TO SEE YOU ON THE OTHER SIDE”; “WHEN THE TIME COME, YOU GOING TO LET US ALL KNOW WHY YOU DIED.” When I visited again, a year later, the messages were there, in the floor with Kevin’s sweat and dreams, but they were invisible beneath a fresh coat of paint.
•
Kevin never knew he had a time bomb inside his chest. But what if he had? At his funeral, friends emphasized that he died doing what he loved. Kevin did love to race. But he loved other things too, like computers. Racing might have been his scholarship ticket, but I have no doubt that he would have stopped running and eagerly rechanneled his competitive energy elsewhere. For me, there is scant solace in the poetic detail that he died running.
While the issue of whether to preemptively restrict an athlete is beset with emotional and legal barbs, cardiologists agree that when an athlete is clearly at risk of dropping dead on the field, the recommendation should be to avoid the field. (Though some athletes ignore the advice and play anyway.) But what if the athlete was just at risk of damage? Sports are inherently risky. Like flying fighter jets, no one participates for too long without an injury. But what if scientists could tell that some athletes are at greater risk than others?
Right now, they are beginning to be able to do just that, as researchers probe genes associated with some of the most high-profile medical risks in all of sports.
•
On a brisk November afternoon in Manhattan, Ron Duguay had just finished several hours of cognitive testing when he settled into a chair overlooking Park Avenue South to await news from Dr. Eric Braverman. Beginning in 1977, Duguay played twelve seasons in the NHL, primarily as a center with the New York Rangers. Duguay was a good player—he made the ’82 All-Star Game—but was better known as hockey’s rock star.
Duguay didn’t wear a helmet, and the curly brunette locks that fluttered behind him when he skated made him a sex symbol in the 1980s. Even today, in his fifties and married to erstwhile supermodel Kim Alexis, Duguay’s hair is thick and curly, and he is friendly and easy to talk to. In Braverman’s office, though, he’s nervous. He fiddles with his gleaming Rangers pinkie ring when he mentions that friends often tell him he should write a book about his hockey days. “I’d have to call up my teammates,” he says. “There’s a lot I can’t remember.” That’s why Duguay is here. He thinks he suffered undiagnosed concussions during his career, and he knows he took scores of lesser hits to the head from sticks, elbows, and the occasional puck.
Braverman appears and flatly tells Duguay that he flunked three of the tests meant to gauge his memory and brain processing speed. “He’s a mess compared to his old self,” Braverman says.
As part of the testing, Braverman also ordered a genetic test to see what versions Duguay has of a gene known as apolipoprotein E, or ApoE. Duguay’s grandmother died from Alzheimer’s disease, and another family member has been having memory problems. Studies of Alzheimer’s patients indicate that a particular version of the ApoE gene substantially increases an individual’s risk of getting the disease.
The gene comes in three common variants: ApoE2, ApoE3, and ApoE4. Everyone has two copies of the ApoE gene, one from Mom and one from Dad, and a single ApoE4 copy increases the risk of Alzheimer’s threefold. Two copies increases the risk eightfold. Around half of Alzheimer’s patients have an ApoE4 gene—compared with a quarter of the general population—and those who do tend to develop the disease at a younger age.
The importance of the ApoE gene extends beyond Alzheimer’s to how well an individual can recover from any type of brain injury. Carriers of ApoE4 gene variants who hit their heads in car accidents, for example, have longer comas, more bleeding and bruising in the brain, more postinjury seizures, less success with rehabilitation, and are more likely to suffer permanent damage or to die.
It is not entirely understood how ApoE influences brain recovery, but the gene is involved in the brain’s inflammatory response following head trauma, and people who have an ApoE4 variant take longer to clear their brains of a protein called amyloid, which floods in when the brain is injured. Several studies have found that athletes with ApoE4 variants who get hit in the head take longer to recover and are at greater risk of suffering dementia later in life.
A 1997 study determined that boxers with an ApoE4 copy scored worse on tests of brain impairment than boxers with similar length careers who did not have an ApoE4 copy. Three boxers in the study had severe brain function impairment, and all three had an ApoE4 gene variant. In 2000, a study of fifty-three active pro football players concluded that three factors caused certain players to score lower than their peers on tests of brain function: 1) age, 2) having been hit in the head often, and 3) having an ApoE4 variant.
In 2002, at age forty, former Houston Oilers and Miami Dolphins linebacker John Grimsley began to show signs of dementia. His family noticed that he would repeat the same question, that he could not remember what groceries to buy without a list, and that he would ask to rent movies he had already seen.
Though an experienced hunting guide, Grimsley accidentally shot and killed himself in 2008 while cleaning one of his guns. Grimsley’s wife, Virginia, had long wondered whether the concussions her husband suffered had anything to do with his mental deterioration, so she donated his brain to Boston University’s Center for the Study of Traumatic Encephalopathy.
It was the first of many brains belonging to former NFL players that the BU researchers would examine en route to increasing awareness of the danger of brain trauma in sports. The researchers at the center found an extensive buildup of protein in Grimsley’s brain, characteristic of chronic traumatic encephalopathy, or CTE. The condition has now been found in scores of brains from college and pro football players. The BU scientists also found that Grimsley—like just 2 percent of the population—had two copies of the ApoE4 gene variant.
In 2009, the BU researchers made national headlines (and headaches for the NFL) when they reported on dozens of cases of brain damage in boxers and football players. What went entirely unmentioned in media coverage, though, was that five of nine brain-damaged boxers and football players who had genetic data included in the report had an ApoE4 variant. That’s 56 percent, between double and triple the proportion in the general population. Brandon Colby, a Los Angeles–based physician who treats former NFL players says of those patients: “Of the ones who have noticeable issues from head trauma, every single one had an ApoE4 copy.” Colby now offers ApoE testing of children to parents who want to weigh the risks of playing football.
Neurologist Barry Jordan, coauthor of the 2000 study of fifty-three football players, and former chief medical officer of the New York State Athletic Commission, once considered making genetic screening for the ApoE4 variant mandatory for all boxers in New York. “I don’t think you can stop an athlete from participating,” Jordan says, “but it might help just in monitoring them closely. [An ApoE4 gene variant] doesn’t seem to increase the risk of concussion, and I wouldn’t expect it to, but it may affect your recovery following concussion.”
Ultimately, Jordan decided not to implement mandatory genetic testing, primarily because he was concerned about how the information could be used. “Even with [the Genetic Information Nondiscrimination Act],” Jordan says, “you never know. Information still gets out. I think genetic testing is something you can educate athletes about. But I’m not sure how interested people would be in it. Some people don’t want to know.” Or, as James P. Kelly, a neurologist who was on the Colorado State Boxing Commission, put it: “With ApoE4, some would argue that knowledge is not power.”
It’s fraught territory, but most current or former pro athletes to whom I explained an ApoE4 test seemed eager to take one, provided the information would be kept from teams, insurance companies, and potential future employers.* Weeks after his visit to Dr. Braverman, Ron Duguay learned that he did indeed have an ApoE4 variant. Had he known of this potential additional risk factor for cognitive impairment, Duguay says he “would’ve seriously considered wearing a helmet” during his playing days.
Among other athletes I asked about their interest in ApoE testing was Glen Johnson, a professional boxer with seventy-one fights, including wins in 2004 over Roy Jones Jr. and Antonio Tarver. Johnson knew that getting hit in the head—and not simply a particular gene—was the primary factor for brain damage, but says, “I’d never hide from extra information.”
Former New England Patriots linebacker Ted Johnson, who suffered a series of concussions that led him to retire and later suffered from amphetamine addiction, depression, memory problems, and chronic headaches, says: “I would be the first person signed up for a test. I wouldn’t even hesitate. I know it’s no guarantee just because you have this gene, but if it’s true that you are potentially at greater risk than the average person, I would do it in a heartbeat. When I was playing we had no information. . . . This kind of information would be incredible to have if you’re a current player.” One Alzheimer’s researcher at Mount Sinai Hospital in New York has noted that the dementia risk of having a single ApoE4 copy is roughly similar to the risk from playing in the NFL, and that the two together are even more dangerous.
But because the precise degree of additional risk is impossible to quantify, doctors I spoke with almost uniformly felt that ApoE testing should not be offered to athletes. “This is a very controversial area,” says Robert C. Green, a BU neurologist who collaborated on the REVEAL Study, which examined how people who volunteer for ApoE screening react when they get bad news. “The world of genetics for decades has suggested that there’s no reason to give people genetic-risk information unless there’s something proven you can do about it.” REVEAL found, though, that people who learned they had an ApoE4 variant did not experience undue dread. Rather, study subjects who got bad news tended to increase healthy lifestyle habits like exercise, which doctors told them might help, even though there is no proven remedy for delaying the onset of Alzheimer’s.
Still, the doctors’ hesitation is understandable. “If we have a gene we know increases your risk of blowing out your knee, if that got into the wrong hands, somebody could decide not to sign a player,” says Barry Jordan, the former New York athletic commission medical officer. “That would be a potential problem.” (Of course, teams already go to great lengths to guess that same information using physical examinations and medical histories.)
Actually, genes have been identified that appear to alter one’s risk of blowing out a knee. Biologists at South Africa’s University of Cape Town have been leading the way in identifying genes that predispose exercisers to injuring tendons and ligaments. The researchers focused on genes like COL1A1 and COL5A1 that code for the proteins that make up collagen fibrils, the basic building blocks of tendons, ligaments, and skin. Collagen is sometimes referred to as the body’s glue, holding connective tissues in proper form.
People with a certain mutation in the COL1A1 gene have brittle bone disease and suffer fractures easily. A particular mutation in the COL5A1 gene causes Ehlers-Danlos syndrome, which confers hyperflexibility. “Those people in the old days of the circus who used to fold themselves into a box, I bet you in most cases they had Ehlers-Danlos syndrome,” says Malcolm Collins, one of the Cape Town biologists and a leader in the study of collagen genes. “They could twist their bodies into positions that you and I can’t because they’ve got very abnormal collagen fibrils.”
Ehlers-Danlos syndrome is rare, but Collins and colleagues have demonstrated that much more common variations in collagen genes influence both flexibility and an individual’s risk of injuries to the connective tissues, like Achilles tendon rupture.* Using that research, the company Gknowmix offers collagen gene tests that doctors can order for patients.
“All we can say to an athlete with a particular genetic profile is that you are at increased risk of injury based on our current knowledge,” Collins says. “It’s no different than saying that smoking a cigarette increases your chance of lung cancer. The difference is that you can stop smoking, but you can’t change your DNA. But there are other factors which you can change. You can modify whatever training you’re doing to reduce risk, or you can do ‘prehabilitation’ training to strengthen the area that is at risk.”
A gaggle of NFL players have already availed themselves of testing for “injury genes” that may predispose them to Achilles tendon injuries or torn ACLs in the knee. Duke University’s football team, as just one example, sought university approval to submit players’ DNA to a researcher on campus who would look for genes that predispose players to tendon and ligament injuries.
So specific genes have now been implicated in sudden death, brain damage, and injury on the field. And now researchers have begun to identify genes that undergird another unpleasant and unavoidable aspects of sports: pain. Genes, it seems, influence our very perception of it.
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In the waning years of a career that spanned thirteen NFL seasons, 3,479 carries, a bevy of broken ribs, several separated shoulders, a couple of concussions, a torn groin muscle, a bruised sternum, and a legion of knee and ankle surgeries, 255-pound running back Jerome Bettis developed a Monday-morning tradition. He would sit at the top of his staircase and scoot down toward breakfast on his butt, one step at a time.
On Sundays, the Steelers expected Bettis to run through people. “That was my skill set,” he says. “It wasn’t like I could run away from them.” In one game against the Jacksonville Jaguars, a defensive player’s thumb came through Bettis’s face mask and broke his nose. Team doctors taped the nose and stuffed it with cotton. That helped, until a head-on collision late in the game propelled the cotton up through his nasal passage, down his throat, and into his stomach. “It was like, ‘Guys, wait a second, the padding is gone,’” Bettis says. “It was the worst.”
No wonder Bettis was unable to walk down the stairs on Monday mornings. The pain was so intense at times that he figured he would have to miss the next game. But once he stepped on the turf Sunday, he never backed down. “When you get on the field, it’s not even a question mark,” Bettis says. “You do your job, by any means necessary.”
Bettis was renowned for his toughness, but he says there are athletes, even in the NFL, who struggle to manage discomfort. “I think some people’s bodies kind of shut down from the pain, and it doesn’t allow them to still have peak performances,” Bettis says. “I saw that problem at times.”
Pain tolerance and pain management are as central to most high-level sports as running and jumping, and just why some people tolerate pain better than others is a topic of research at the Pain Genetics Lab at McGill University in Montreal. One room in the lab is stacked from floor to ceiling with clear tanks that house mice, all bred for the study of genes that influence how they (and humans) experience pain, and how that pain can be ameliorated.
In one tank are mice missing oxytocin receptors. They are used in the study of pain, but the mice also have deficits in social recognition. Put them with mice they grew up with and they won’t recognize them. In another corner is a tank of raven-haired mice that were bred to be prone to head pain, that is, migraines. They spend a lot of time scratching their foreheads and shuddering, and they are apparently justified in using the old headache excuse to avoid mating. “This experiment has taken years,” says Jeffrey Mogil, head of the lab, of the work that seeks to help develop migraine treatments, “because they breed really, really badly.”
On another shelf is a tank of mice with nonfunctioning versions of the melanocortin 1 receptor gene, or MC1R. In plain language, they’re redheads. It’s the same gene mutation that is responsible for the ginger locks of most human redheads. Mogil found that both people and rodents with the redhead mutation have higher tolerance for certain types of pain, and require less morphine for relief.
MC1R was among the first genes identified that influence how humans experience pain. Another was discovered by scientists who followed the theatrical talents of a ten-year-old Pakistani street performer.
Medical workers in Lahore knew the boy well, because after he stuck knives through his arms and stood on burning coals he would come in to get stitched back together. But they never treated him for pain. The boy could feel no pain.
By the time British geneticists traveled to Pakistan to study him, the boy had died, at the age of fourteen, after jumping off a roof to impress his friends. But the scientists found the same condition in six of the boy’s extended relatives. “None knew what pain felt like,” the scientists wrote, “although the older individuals realized what actions should elicit pain (including acting as if in pain after football tackles).”
The “older individuals” were just ten, twelve, and fourteen. People born with congenital insensitivity to pain tend not to live very long. They don’t shift their weight when sitting, sleeping, or standing as the rest of us do instinctively, and they die from the joint infections that result.
Each of the Pakistani relatives with pain immunity had a very rare mutation in the SCN9A gene. The mutation blocked pain signals that normally travel from nerves to the brain. A different mutation in SCN9A causes those who carry it to be hypersensitive to pain, bothered by warmth so easily that they won’t wear shoes. In 2010, the British geneticists teamed up with researchers in the United States, Finland, and the Netherlands for a study that reported that much more common variations in SCN9A influence how sensitive adults are to common types of pain, like back trouble. Genetic variation among individuals, it seems, ensures that none of us can truly know another’s physical pain.
The gene that has been most studied for its involvement in pain modulation is the COMT gene, which is involved in the metabolism of neurotransmitters in the brain, including dopamine. Two common versions of COMT are known as “Val” and “Met,” based on whether a specific part of the gene’s DNA sequence codes for the amino acid valine or methionine.
In both mice and humans, the Met version is less effective at clearing dopamine, which leaves higher levels in the frontal cortex. Cognitive testing and brain imaging studies have found that subjects with two Met versions—both animals and humans—tend to do better on and require less metabolic effort for cognitive and memory tasks, but that they are also more prone to anxiety and more sensitive to pain. (Anxiety, or “catastrophizing,” is a strong predictor of an individual’s pain sensitivity.) Conversely, Val/Val carriers seem to do slightly worse on cognitive tests that require rapid mental flexibility, but may be more resilient to stress and pain. (They also get a better boost from Ritalin, which increases dopamine in the frontal cortex.) Additionally, COMT is involved in metabolism of norepinephrine, which is released in response to stress and has a protective effect.
David Goldman, chief of the Laboratory of Neurogenetics at the NIH’s National Institute on Alcohol Abuse and Alcoholism, coined the phrase “warrior/worrier gene” to describe the apparent tradeoffs of the two COMT variants. Both versions are common everywhere in the world they’ve been studied. In the United States, Goldman says, 16 percent of people are Met/Met; 48 percent are Met/Val; and 36 percent are Val/Val, leading him to suggest that both warriors and worriers are needed in every society, so there is widespread preservation of both forms of the gene. “We’ve never done the study,” Goldman says, “but I predict if I took a big group of NFL linemen that they would tend to have the Val genotype, because they’re in the trenches every day and they’re exposed to pain and they just have to have this super resilience and toughness.” *
In fairness, studies of the COMT gene have often been contradictory, and the gene’s relevance to pain sensitivity is hotly debated among pain researchers. But the idea that genes involved in emotional regulation might alter pain sensation is uncontroversial. Morphine, after all, doesn’t so much decrease pain intensity, but rather reduces the emotional unpleasantness that results from pain. “The pain circuitry is shared so strongly with the circuitry of emotion,” Goldman says, “and many of the neurotransmitters are too. As you modify emotion, you strongly modify pain response.”
And sports can be strong modifiers.
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Haverford College psychologist Wendy Sternberg was giving a lecture on stress-induced analgesia—the brain’s ability to block pain in high-pressure situations—when a student told her that it sounded just like what happens to athletes in competition.
A 2004 Ultimate Fighting Championship heavyweight title fight is an excruciating example. Brazilian jiu-jitsu black belt Frank Mir caught 6'8" Tim “The Maine-iac” Sylvia in a joint lock called an armbar. Mir grabbed Sylvia’s extended right arm, braced the elbow joint against his hip, and pulled backward so forcefully it looked as if he were heaving back a train brake.
The pop of Sylvia’s shattering arm was audible on television. Referee Herb Dean rushed in to separate the fighters and shouted for the match to stop. Sylvia set to cursing and demanding that the fight continue. Only later, as he sat on a gurney en route to the hospital, did Sylvia begin to feel pain and realize that his attempt to keep fighting had been ill considered. It took three titanium plates to rig his arm back together. “[The ref] probably saved my career,” Sylvia says, because in the heat of battle he couldn’t perceive the pain on his own.
Says Sternberg, “Under conditions of acute stress the brain inhibits pain, so you can fight or flee without worrying about a broken bone.” A system to block pain in extreme situations evolved in the genes of all humans, and even quotidian sports settings tap into it.
In 1998, prompted by her student’s suggestion, Sternberg tested the sensitivity of Haverford track athletes, fencers, and basketball players to cold and heat pain two days before they competed, on the day of a competition, and two days later. She found that basketball players and runners were less sensitive to pain than their nonathlete peers to begin with, and that all of the athletes were least sensitive to pain on game day. “I think athletic competition can activate the fight-or-flight mechanism,” Sternberg says. “When you get in a competition that you care about, you’re going to activate it.”
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Pain can be modified by a game situation or by the emotions of an athlete, but the genetic blueprint for pain in the body is encoded in the brain, whether or not that body even exists in its entirety. (People who are born without limbs or who have them amputated nonetheless often experience pain in those “phantom limbs.”) Still, pain must be practiced in the first place.
In the 1950s, Canadian psychologist Ronald Melzack was working toward his Ph.D. at McGill under psychologist D. O. Hebb, who was studying how extreme deprivation of life experience affects intellect. Hebb was experimenting on Scottish terriers.
The dogs were well cared for, groomed, and fed, but they were totally isolated from the outside world. Hebb was interested in how that would alter their ability to navigate a maze. (The answer: very negatively.) But it was in the holding room, before the maze, where Melzack made the observation that started him down the road to becoming the most influential pain researcher in the world. “The water pipes in the room were at head level for the dogs,” Melzack says, “and these wonderful dogs would run around and bang their heads right into the pipes, as if they felt nothing. And they kept running around and banging their heads on the water pipes.”
Melzack was a smoker at the time, so he struck a match. “I held it out, and they’d put their nose in it,” he says. They’d back up, “and then come back and sniff it again. I’d put it out and light another match, and they’d sniff it again and again.” The dogs obviously had normal cerebral hardware, but had missed the critical developmental window for downloading the brain’s pain software. They never learned to be deterred by the flame. Just like language, or hitting a baseball, even though each of us may be born with the requisite genetic hardware, if we miss the window for acquiring the software, the genes are of little use. Adds Jeffrey Mogil, of McGill’s Pain Genetics Lab: “The fact that something like pain would have to be learned at all is pretty surprising.”
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Pain is innate, but it also must be learned. It is unavoidable, and yet modifiable. It is common to all people and all athletes but never experienced quite the same way by any two individuals or even by the same individual in two different situations. Each of us is like the hero in a Greek tragedy, circumscribed by nature, but left to alter our fate within the boundaries. “Maybe if you’re a worrier by genotype, it’s a better idea not to be a warrior by profession,” says Goldman, the neurogeneticist. “Then again, it’s hard to say, because people overcome so much.”
Like most traits discussed in this book, an athlete’s ability to deal with pain is a braid of nature and nurture so intricately and thoroughly intertwined as to become a single vine. As one scientist told me: without both genes and environments, there are no outcomes.
It reinforces the idea that any notion of finding an “athlete gene” was a figment of the era of wishful thinking that crested a decade ago with the first full sequencing of the human genome, before scientists understood how much they don’t understand about the complexity of the genetic recipe book. What, exactly, most human genes do is still a mystery. Sure, the ACTN3 gene may tell a billion or so people in the world that they won’t be in the Olympic 100-meter final, but chances are they all already knew that.
If thousands of DNA variations are needed to explain just a portion of the differences in height among people, what are the chances of ever finding a single gene that makes a star athlete? Slim? Or none?
And yet . . .
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