Published: Feb. 27, 2013 By

BioFrontiers scientist tackles a childhood disease of the heartA cardiomyocyte imaged by the BioFrontiers Advanced Imaging Facility.

BioFrontiers Chief Scientific Officer Leslie Leinwand, has been studying the motor protein, myosin, for 25 years. This important protein is responsible for making muscles contract, including one vital muscle: your heart. 

Myosin drives heart muscle contraction, and when this protein is mutated, it has devastating effects on the cardiovascular system. There are more than 300 known mutations in myosin, many of which cause a disease called hypertrophic cardiomyopathy. Hypertrophic cardiomyopathy is the most common genetic heart disease, occurring in 1 in 500 individuals, and it is the leading cause of sudden death in young people. In hypertrophic cardiomyopathy, the heart muscle becomes thickened in parts, forcing the heart to work overtime pumping blood throughout the body.

Many adults manage this disease successfully by avoiding strenuous, competitive exercise and using a pacemaker. Children with this disease don’t have as many options as adults.

“Pediatric patients have a much more difficult time with this disease,” says Leinwand. “Some of the myosin protein mutations appear only in infants and young children, and these cause a version of the disease that is much more aggressive. Heart transplants are difficult at this age, but without them these patients have about a 40 percent mortality rate.

There are 1,000 to 5,000 new cases of pediatric hypertrophic cardiomyopathy diagnosed each year. The pediatric disease is relatively rare, with twelve children diagnosed out of every million, and the majority of patients are diagnosed before their first birthdays. Beyond the clear genetic causes, the other causes of the disease in children are not well understood and research on the subject is sparse. Fewer than 25 percent of these childhood cases have an identifiable cause, despite standardized and rigorous testing.

Leinwand recently won a $45,837 grant from the Children’s Cardiomyopathy Foundation (CCF) to study the differences in the myosin mutations in adult and pediatric populations. She also plans to look at the effects of a small molecule drug on the pediatric versions of the protein in a test tube. This small molecule drug has promise for treating adults with heart failure.

“Dr. Leinwand’s work in the field of cardiovascular genetics and muscle biology is impressive, and CCF is excited to support her study on pediatric hypertrophic cardiomyopathy. Because there are so few therapeutic options for children with this inherited heart disease, her findings could have a significant impact on how children are treated and their outcomes,” says CCF Founder and Executive Director Lisa Yue.

“We would like to get beyond just treating the symptoms, and I believe we have the potential to treat the root cause of this disease,” says Leinwand. “If we can focus on preventing the heart muscles from thickening in the first place, we can get away from pacemakers and transplants, and have more success in giving these young patients a better chance in living with this disease.”