Heart Disease Gene Discovery Strengthens Skeletal Disease Link

The latest discovery by Dr. Jeffrey A. Towbin, a professor of pediatric cardiology at Baylor, and his research team is reported in the March 6 issue of the journal Circulation. It identifies alpha-dystrobrevin, a cytoskeletal protein, in left ventricular disease. The research also confirms that mutations in the gene G4.5 result in a wide spectrum of heart muscle disease.

"If you have muscle disease, you have muscle disease," Towbin said. "It's intriguing that all of the cardiomyopathy genes lead to skeletal myopathy as well."

In identifying genes associated with structural heart disease, or cardiomyopathy, the Baylor team is focusing on finding the "final common pathway" that links heart muscle disease. Towbin said it is important for physicians to recognize the connection between structural heart disease and skeletal and muscle disorders. "There's this big picture that cardiologists, neurologists, general practitioners, family doctors and pediatricians all need to understand," he said.

For example, based on this link between muscle and heart disease, patients with muscular dystrophy should be screened early for heart disease. In the past, muscular dystrophy patients often were sent to a cardiologist after their heart disease had developed to a point where treatment was limited, said Towbin, who also serves as associate chief of pediatric cardiology at Texas Children's Hospital.

"If we can intervene early, before the patient has significant disease and essentially no symptoms, we can support the heart muscle for an extended period of time," he said.

Towbin said each of these gene discoveries is adding to the understanding that heart disease is associated with a complex interaction of proteins.

"In cardiac disease, it's not one gene and one protein that causes the problem. It's many proteins and genes and in most cases, the gene mutations are specific to the individual," he said. "Your mutation is not likely to be the same as anyone else's, except those in your family."

These findings will lead to better patient care, Towbin said, both through new targeted therapies and early intervention when heart muscle disease can be anticipated.

Other members of the research team included Fukiko Ichida, Shinichi Tsubata, Karla R. Bowles, Noriyuki Haneda, Keiichiro Uese, Toshio Miyawaki, W. Jeffrey Dreyer, John Messina, Hua Li and Neil E. Bowles.