At the Association for Molecular Pathology's annual meeting in San Jose last week, Harvard Medical School's Jonathan Seidman made a case for the importance of studying rare genetic variants that cause cardiomyopathy. Various genes cause different pathway mutations that lead to cardiomyopathy, Seidman said, and cardiologists can't distinguish between them. While there are several common variants, there are multiple rare variants that can significantly increase a patient's chances of suffering from the disease. Seidman pointed to a study done in India that showed that 4 percent of Indians — about 44 million people — have one rare variant that increases their risk of cardiomyopathy seven-fold. So, he added, finding which variant cardiomyopathy patients have can also be beneficial for identifying what kind of risk their family members have for developing the disease. Seidman and his team of researchers are continuing to sequence and search for novel variants. He believes the full set of genetic variants will be identified by the end of 2011 or early 2012.
The University of Chicago's Elizabeth McNally added that when it comes to testing for inherited cardiovascular diseases, researchers and clinicians have to focus on rare variants, as they tend to be unique to families, can predict risk, and can inform a physician's choice of therapy.