Genetic Roots of Rare but Often Fatal Heart Condition in Young Athletes

The stories of young athletes who die suddenly while engaging in athletic activity grace the front of local newspapers on a seemingly regular basis. People often wonder how this could have happened and what was the cause.

Dr. Daniel P. Judge and a team of colleagues have done a study through John Hopkins to try to get some answers to those questions. According to Judge, the condition that causes most cases of sudden death during athletic activity is known as ARVD ((arrhythmogenic right ventricular dysplasia). Judge says the case that brought his program's attention to the matter was a case in which a father and daughter both died suddenly during athletic activity. The family members wanted to know what the cause was and what was the risk of having the same thing happen to them. In addition to the usual round of cardiac testing (stress tests, EKG, echocardiogram, cardiac MRI and electrical heart monitoring), Judge says his team really sought to have a blood test that could help to identify those who had the greatest risk for ARVD.

What the study found is that mutations in a gene called plakophilin-2 (PKP2) are the most likely culprit of ARVD, which is one of the leading causes of sudden cardiac death among young athletes. ARVD is characterized by a dysfunctional right ventricle, which beats irregularly and weakens the muscle over a period of time because of excess fat and scar tissue buildup. It can trigger a rhythm disturbance in the heart, which causes death, if left untreated.

"We believe we have pinpointed the genetic mutations responsible for the syndrome in many people, and we expect to have a blood test to identify those at greater risk of developing ARVD clinically available within the next couple of months," said Judge. "Genetic testing is gradually entering clinical practice. Use of such testing appears to be a good way to identify family members of people with this condition who are at greatest risk of sudden death."