Study reveals how Duchenne muscular dystrophy causes heart r
Abnormalities in the proteins responsible for transmitting electrical signals in the heart likely cause abnormal heart rhythms in patients with Duchenne muscular dystrophy(DMD). They collected skin biopsies of 3 DMD people and two healthy volunteers. When they measured electrical activity in the newly formed heart cells, they found that cells from people with DMD had slower electrical signals, generated arrhythmias, and were less able to contract than cells from people without the condition. Individuals with DMD also had less potassium and sodium ions flowing in their cell membranes, both essential for electrical signaling in the heart. They also found that heart muscle cells grown from males with DMD had less sodium and potassium ion channels, which control the flow of sodium and potassium than people without the condition. But adding an essential partner protein of sodium and potassium channels called ?1-syntrophin to the cells of one of the males with DMD corrected electrical activity in the cells and prevented abnormal rhythms.