A potentially life-changing heart condition, dilated cardiomyopathy , can be caused by the cumulative influence of hundreds or thousands of genes and not just by a single "aberrant" genetic variant, as was previously thought, finds a new study led by researchers at UCL (University College London), Imperial College London and the MRC Laboratory of Medical Sciences. Dilated cardiomyopathy (DCM) is a condition in which the heart becomes progressively enlarged and weakened, reducing its ability to pump blood efficiently. It is estimated to affect up to 260,000 people in the UK (one in every 250 individuals) and is the leading cause of heart transplantation.
Previously, it was thought that dilated cardiomyopathy was mostly caused by faulty copies of a single gene that can be passed down through families, even though in more than half of patients no faulty gene is identified. The new study, published in the journal Nature Genetics , found that about a quarter to a third of the risk of dilated cardiomyopathy could be accounted for by the small effects of many thousands of genetic differences scattered throughout the genome. Importantly, the researchers also developed a polygenic risk score to assess a person's likelihood of developing dilated cardiomyopathy based on the many small effects of these genes.
They found that those with the highest genetic risk score (in the top 1%) had a fourfold risk of developing dilated cardiomyopathy compared to those with an average risk score. In a.