Hypertrophic cardiomyopathy (HCM), an inherited disease that can cause the heart to thicken and stop pumping blood effectively, leading to heart failure.
HCM can result from different mutations of many proteins in the heart. One of those proteins, myosin, acts as a tiny molecular motor in every heart muscle cell. It pulls and releases on a rope-like protein, actin, in order to make the heart muscle contract and relax as it pumps blood.
A mutation of myosin can "alter the motor's power-generating capacity" and make the heart work improperly, which in turn causes the heart to enlarge.
For many years, scientists assumed that the mutation caused the myosin to lose its motoring power, throwing off the whole heart engine. But in a study Warshaw published in 2000 in Circulation Research, he and colleagues found that the problem wasn't diminished power in the myosin; it was too much power with this mutation.
The team of scientists found a way to address this problem - which they report in the journal Science. Using mice bred with the mutation, the team tested a small molecule inhibitor that dials back the myosin motor's power generation to a more normal level. The mice got the drug containing the molecule as early as eight weeks old, and amazingly it prevented the HCM from surfacing, according to the study.
"When they gave the drug to a young mouse with the mutation, the mouse's heart developed normally," Warshaw says.
Because HCM runs in families, an infant who tests positive for the genetic mutation could receive the treatment and stave off the disease. Development of a human drug, however, would require much more extensive testing and many remaining questions to be answered.