In September, a biotech company started up in San Francisco with a goal of using a novel genomics-based approach to developing drugs for cardiomyopathy, a life-threatening heart condition that affects 60 million people worldwide. The company, called MyoKardia, is going after people who have genetic mutations that cause some forms of the condition, planning to market its drugs alongside diagnostic tests that identify the patients most likely to respond. Boston-based venture capital firm Third Rock Ventures launched MyoKardia with a $38 million investment.

MyoKardia scientists are developing drugs that address a subset of mutations in the sarcomere, the basic unit of heart muscle. Third Rock partner Charles Homcy, the company's interim CEO, says scientists now understand mutations well enough to "match the genotype to the phenotype," or the individual's genetic mutations to the specific characteristics of his or her disease. MyoKardia is developing drugs that will be targeted to patients on the basis of both genotypes and phenotypes, he says.

Some cardiologists say they would welcome a more targeted approach to treating cardiomyopathy. "Several mutations have been found, but we don't know exactly how they work, and we do not know how to treat them," says Daphne Hsu, chief of pediatric cardiology at Montefiore Medical Center in New York. "All we can do now is treat symptoms. If genetics could lead to better therapies, that would be wonderful."