Isaiah Austin’s decision to enter and then withdraw from Thursday’s National Basketball Association Draft could end up saving his life. Medical testing conducted as part of May’s NBA Combine, a series of workouts that gives teams an opportunity to evaluate draft prospects, revealed that Austin suffers from Marfan’s syndrome. The connective tissue disorder likely contributed to the seven-foot, one-inch frame that helped Austin excel at basketball. The condition also puts him at high risk for a thoracic aortic aneurysm—swelling in the upper part of the large artery that carries blood from the heart, down through the chest and into the abdomen that can strike without warning and is often fatal if not monitored closely.
The diagnosis came as a heartbreaking surprise for Austin, whose basketball career ended just days before the opportunity to go pro. Yet it was genetic testing performed in preparation for the draft that tipped doctors off to a serious medical problem that had previously eluded diagnosis.
Marfan’s syndrome results from a gene mutation that leads the body to overproduce a particular protein—called transforming growth factor beta (TGF-β)—causing problems in connective tissue that holds all bodily cells, organs and tissue together. Those afflicted with Marfan’s are highly susceptible to an abnormal widening or ballooning of their arteries because the walls have been weakened.
Athletes engaging in intense physical exertion are particularly vulnerable to an aortic aneurysm when their blood pressure rises too high. Such was the case with six-foot, five-inch U.S. Olympic volleyball star Flo Hyman, who died in January 1986 at the age of 31 from a ruptured aorta—the result of Marfan’s syndrome—during a match in Japan.
To better understand how Marfan’s puts athletes at risk as well as the treatments available, Scientific American spoke with John Elefteriades, director of the Center for Thoracic Aortic Disease at Yale University and a professor of surgery. Elefteriades, who wrote “Beating a Sudden Killer” about the danger of aneurysms in Scientific American’s August 2005 issue, says he and his colleagues are on a mission to find athletes suffering undiagnosed Marfan’s before it is too late for them.
[An edited transcript of the conversation follows.]
What is the connection between Marfan’s and the risk of a thoracic aortic aneurysm?
Patients with Marfan’s disease very, very often develop aneurysms on top of the heart in the ascending aorta. A person’s connective tissue—like the girders inside a building—is vitally important to keeping their organs together. This is especially true of the aorta, which bears the burden of accepting every heartbeat. The framework for the aorta is weak in someone with Marfan’s disease, so it’s like a building whose girders are made of deficient steel. The aorta stretches out over time. Bones and joints are also affected by the disease, and the lenses in the eyes tend to dislocate. [Austin suffered a detached retina as a teenager and ultimately needed to have that eye replaced with a prosthetic.] Hernias—bulging of the intestines through the tissue that’s supposed to hold them back—are also common.
How common is Marfan's syndrome?
I usually say one in 10,000 people in the U.S. have Marfan's syndrome. The genders are equally represented in that number, and I’m not aware of any racial predilection toward the condition.
How often is the condition fatal?
Marfan’s disease used to always be fatal—a person wouldn’t normally live past the age of 45. Today, with aggressive treatment, people can live well beyond that. One of the difficulties is that in patients with Marfan’s disease you tend to chase the aorta. This means you might fix an aneurysm in the upper aorta with a Dacron graft, but the downstream, or lower part of the aorta, will need additional grafts over time.
Why might Austin’s condition not have been diagnosed sooner?
When a physician looks at a basketball team, all we see are potential cases of Marfan’s—people who are extremely tall and thin, for starters. Actually, Marfan’s patients make good athletes because their bodies can contort in ways that other people’s cannot. I’m not saying that a large proportion of basketball players do have Marfan’s, but their appearance alone is similar to a person with that condition.
How is Marfan’s syndrome typically diagnosed?
Testing today is done by reading a person’s whole genome. We charge about $3,000 for such a test, and it’s getting cheaper. Previously Marfan’s disease was diagnosed only with the help of special tests done in specific laboratories, and it wasn’t based on reading the whole genome. My colleagues and I are on a quest to test all college athletes. If you have an aneurysm during high-intensity sports, you can tear the aorta easily. I could tell you stories that would make you cry—about athletes who had an unknown aneurysm and succumbed on the field or in the gym. Cardiac echo is a well-established technique to view the heart using sound waves. We’ve developed a simplified echo protocol that is limited to examining for conditions that can threaten an athlete’s life. This ultrasound test can be performed by a trainer and read by an echo specialist for a cost of $250 or less. The sound waves enable you to see the ascending aorta very well and check whether it’s enlarged.
What risks would Austin face if he continued his basketball career?
When there is underlying aortic enlargement and situations occur in which blood pressure rises very high, the inner lining of the aorta tears. This is known as an aortic dissection, and the layers of the lining peel apart. If you have an aneurysm, it won’t usually rupture unless the blood pressure rises very high. That’s the fear with these athletes—that under physical duress, their blood pressure will rise and their enlarged aorta will tear.
How might a weakened aorta impact Austin’s ability to exercise and remain active the rest of his life?
The good news is that aerobic exercise is reasonably safe because the associated rise in blood pressure is quite modest. Basketball is highly aerobic, but it’s also high intensity, which makes it dangerous. I see athletes from all over the world to advise them on the dos and don’ts. By and large, I permit aerobic exercise to 75 percent of their maximum capacity. With weight lifting, I allow up to 50 percent of the body weight when, for example, bench pressing. We're working to provide more precise guidelines based on experiments with athletes.
Are there different degrees of Marfan's syndrome?
There are different degrees of penetrance [expressed genetic effects]. Marfan’s is a dominant gene, so a person with this condition has a high likelihood of passing it down. Still, you can have the gene but not get the whole problem—in other words you would have a low penetrance. In that case, you might have great height but no aneurysm or you might not be very tall yet develop an aneurysm. Most people with Marfan's have the whole thing, but it’s not uncommon for someone to have part of the symptoms. When that does happen, it’s very hard to diagnose because it doesn’t shout out at you.
How can Marfan's be treated?
Once you’ve diagnosed someone with Marfan’s—that’s the hardest part—it can then readily be treated. In extreme cases the treatment would be to replace the aorta with a tube made of Dacron. If the aorta’s diameter is five centimeters or more—about the diameter of a Coke can—we recommend replacement. Once the aorta has been replaced, if it’s successful, the patient can go back to heavy exercise. There are medications that can treat those Marfan's aortas not ripe enough for surgery. One is a beta-blocker, which decreases the strength of the heartbeat. The other category consists of Angiotensin II receptor blockers, or ARBs. There’s evidence from Johns Hopkins University and Harold Dietz that this can prevent problems with the aorta.
In your 2005 Scientific American article you mention one symptom of Marfan’s being the ability to cross the thumb all the way over the palm while keeping the hand flat. Is this something that people who suspect they might have this condition should try?
I really do recommend it. If, when you cross your thumb across the palm, the fingernail reaches well beyond the edge of the palm, that could be a sign of Marfan's syndrome or another similar syndrome.