Hypertrophic cardiomyopathy, characterized by an abnormal thickening of the heart muscle, most commonly affects the left ventricle, the main pumping chamber of the heart.
Over the past several decades, researchers have discovered that many heart diseases are genetic (inherited), resulting in changes in how these diseases are diagnosed and managed.
“We believe that in cases of inherited heart disease, it is extremely important to focus care on the entire family,” explains Dr. Carolyn Ho, Medical Director of the Cardiovascular Genetics Program at Brigham and Women’s Hospital (BWH). “In addition to developing and delivering therapies that are tailored for patients with inherited heart disease, we work closely with their families to identify those at risk of also developing the disease.”
One of the most common genetic heart diseases is hypertrophic cardiomyopathy (also known as HCM), which affects between one in 500 and one in 1,000 people in the general population. HCM is characterized by an abnormal thickening of the heart muscle. The left ventricle, the main pumping chamber of the heart, is most commonly affected. BWH researchers determined that HCM is caused by mutations in a group of related genes within the sarcomere, a network of proteins that make up the molecular motor of the heart and coordinate the contraction and relaxation of the heart muscle. Other examples of inherited heart disease include Marfan syndrome, genetic dilated cardiomyopathy, and inherited cardiac arrhythmias.
Genetic testing can be used to help pinpoint the cause of disease in a particular family by finding changes or mutations in DNA. Typically, testing begins with the family member that has the most severe manifestations of disease. If genetic testing confidently identifies the mutation responsible for causing the condition, more focused follow-up testing can be extended to other at-risk family members. In HCM, for example, first-degree relatives (parents, siblings, and children) of people with HCM have a 50 percent chance of inheriting the disease-causing mutation and developing HCM as well. Interpreting the results of genetic testing can be very complicated, so it is important for families to work with a team that includes a genetic counselor, as well as specialists who can evaluate and monitor family members for early subtle changes in the heart that can indicate the development of disease.
In the BWH Cardiovascular Genetics Center, experts are evaluating ways to prevent the development of inherited heart diseases in at-risk family members. They are currently conducting clinical trials investigating whether certain medications can delay the onset or slow the progression of HCM and genetic dilated cardiomyopathy in select patients.
Learn more about inherited heart disease in the following video featuring Dr. Ho.– Jessica F.