8% Indians carry mutated gene associated with heart failure
16 Jan 2015
A new study had revealed that up to 8 per cent of Indians and other South Asians carried a gene mutation that caused heart failure and potentially fatal heart attacks.
The study led by Sakthivel Sadayappan, PhD, MBA, of Loyola University Chicago Stritch School of Medicine demonstrated how this gene mutation impaired the ability of the heart to pump blood. The results of the study could point the way to eventual treatments and prevention strategies.
The mutation caused hypertrophic cardiomyopathy, the most common form of inherited cardiac disease and the leading cause of sudden cardiac death in young people. People who carried the mutated gene had 80 per cent chance of developing heart failure after age 45.
The mutated gene encodes a protein, called cardiac myosin binding protein-C (cMyBP-C), which controlled cardiac muscle contractions and was critical for normal functioning of the heart.
In the mutated gene, 25 base pairs (DNA letters) are missing resulting in alteration of the tail end of the protein.
According to experts, the findings could lead to treatment involving replacement of the mutant protein with normal cMyBP-C protein.
The study was published in the Journal of Biological Chemistry, a publication of the American Society for Biochemistry and Molecular Biology.
The mutation was first reported by Dr Sadayappan in 2001 at the World Congress of the International Society for Heart Research. He said that based on a report from one of his collaborators, the mutation is likely to have occurred in a single individual roughly 33,000 to 55,000 years ago which then spread throughout South Asia.
In his new study, Sadayappan and colleagues introduced the mutated gene into adult rat cardiomyocytes (heart muscle cells) in a petri dish which were then compared with cardiomyocytes that received a normal gene.
In cells that carried the mutant gene, sarcomeres, the basic units of heart muscle did not incorporte the cMyBP-C protein.
The protein rather than helping the sarcomeres contract properly, merely floated around the cell's cytoplasm, causing a toxic effect. The study showed, for the first time, that expression of the mutant protein was sufficient to cause cardiac dysfunction.
