Hiding in Plain Sight: The CD36 Variant Gene Panels Missed

Key Takeaway: A large study of 82,623 people of African ancestry found that a common variant in the CD36 gene is linked to a nearly fivefold higher risk of dilated cardiomyopathy in people who carry two copies. Because the variant is so widespread, it appears to account for more than twice as much of this form of heart failure in this population as titin mutations, the gene long taught as the leading genetic cause.

The Culprit Hiding in Plain Sight

Picture a 38-year-old man who climbs the stairs to his apartment one evening and has to stop halfway, gasping. A week later an ultrasound shows that his heart has stretched into a thin-walled, weakly beating balloon. His doctors order a genetic panel and look for the usual suspect, titin. The result comes back negative, and the chart reads “idiopathic,” which is medical shorthand for “we don’t know why.”

Many patients like him have received that answer. Since a landmark 2012 study, truncating mutations in titin, the giant spring-like protein that gives heart muscle its elasticity, have been…