Members of a family beset by early-onset heart disease are participating in an NIH study aimed at identifying genetic causes of the condition. The research project, under the direction of Dr. Leslie Biesecker, will seek a rare genetic aberration or mutation that causes advanced heart disease in otherwise healthy people such as the members of the Del Sontro family, a number of whom have been diagnosed with the condition in their 30s and 40s, even in the absence of common risk factors such as high cholesterol. "We don't know yet how many pathways there are to heart disease," Biesecker said. "That's the power of genetics. To try and dissect that."