Genetic Variant Tied to Dangerous Arrhythmia

Ser96Ala linked to heart rhythm dysfunction and sudden cardiac death

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Certain types of heart arrhythmias may be dangerous and are associated with an increased risk of sudden cardiac death. Now researchers have found a genetic variant that appears to be associated with an increased risk of both.

Named Ser96Ala, researchers identified the genetic variant in a heart protein and found that it can be linked to heart rhythm dysfunction.

"Exercise regularly to improve heart failure symptoms."

Vivek Singh, PhD, a research scientist at the University of Cincinnati, said the recently identified variant in a histidine-rich calcium-binding protein showed a significant association with worsening arrhythmia and sudden cardiac death in patients with idiopathic dilated cardiomyopathy, a condition with an unknown cause in which the heart becomes enlarged and weakened and does not effectively pump blood. About a third of heart failure cases are caused by dilated cardiomyopathy.

Dr. Singh noted that sudden cardiac death is a risk for heart failure patients who carry the variant because the calcium in their hearts is not properly controlled, potentially leading to the development of arrhythmias. Histidine-rich calcium-binding protein regulates calcium uptake and release, and plays an important role in heart contractions.

The genetic variant marks the first discovered in dilated cardiomyopathy patients and could open the door for new treatments.

Investigators performed tests in animal models with both normal and altered cells, finding that heart cells had significantly reduced ability to contract with disturbed calcium regulation. Tests on the altered cells, or those with the genetic variant, also were more likely to demonstrate arrhythmic behavior under stressful conditions.

Dr. Singh said the findings could be used to develop tests to screen patients and prevent arrhythmias in carriers of the genetic variant.

The research, funded by an American Heart Association Fellowship Award and the National Heart, Lung, and Blood Institute of the National Institutes of Health, was presented today at the International Society of Heart Research's Pathology and Treatment of Heart Failure meeting in Banff, a town within Banff National Park in Alberta, Canada.

Reviewed by: 
Review Date: 
May 29, 2012
Last Updated:
May 30, 2012