Scientists have narrowed down the harmful mutations that cause dilated cardiomyopathy, the leading cause of inherited heart failure, which could lead the way to better screening and more accurate diagnosis.
The study, published in Science Translational Medicine, clarified which titin mutations are linked to disease and which are benign variations.
'These results give us a detailed understanding of the molecular basis for dilated cardiomyopathy,' said lead author Professor Stuart Cook from Imperial College London.
'We can use this information to screen patients' relatives to identify those at risk of developing the disease, and help them to manage their condition early.'
Titin is a large protein that contributes to heart muscle elasticity. Most mutations in its gene make the protein smaller, or truncated. But as about one in 50 people have a titin truncation and most are healthy, the use of the protein in screening for the condition has been limited.
The study's results showed that the crucial titin mutations that cause dilated cardiomyopathy are located at the far end of the gene sequence. Meanwhile, the harmless mutations seen in healthy individuals were found in parts of the gene that do not participate in the formation of the final form of the protein, leaving titin unaffected and functional.
It is estimated that dilated cardiomyopathy affects one in 250 people. People with the condition develop a thin, weak and irregular-beating heart muscle and frequently need a heart transplant. Family members of people with the condition have regular heart screenings as they are at risk of the disease too.
Professor Jeremy Pearson, associate medical director of British Heart Foundation, which partly funded the study, said: 'This study defines, for the first time, a comprehensive list of mutations in the titin gene, which of these are related associated with dilated cardiomyopathy, and which are harmless. This information will be extremely valuable for correct future diagnosis and treatment as we enter an era when many people’s genes will be sequenced.'