A collaborative international investigation led by British Heart Foundation (BHF) and Wellcome Trust funded researchers has identified a potential genetic cause for a serious form of congenital heart disease (CHD).
Congenital heart abnormalities are a relatively common form of birth defect, affecting around seven in every 1000 babies, often with very severe effects. In some cases the heart abnormalities are associated with genetic or chromosomal disorders such as Down’s syndrome, or with harmful environmental exposures during gestation, but in most the cause is unknown.
Half a million common genetic variants were analysed from more than 2000 CHD patients, and more than 5000 healthy controls. A variant close to the MSX1 and STX18 genes on chromosome 4 was found to be associated with the risk of atrial septal defect (ASD) – a hole between two chambers of the heart – and this association was confirmed in a smaller additional group of cases and controls, although the variant is reported to be linked with only around 10% of ASD cases. This research is therefore a small, first step towards unravelling the complex genetic contributions to congenital heart defects.
Though no longer newsworthy, progress in deciphering the genetics of many diseases and birth defects is crucial for understanding the processes by which disease occurs, and large-scale international studies are necessary to achieve this. Lead researcher Professor Kevney of the University of Manchester said genetic insights into normal heart development were: "fundamental to any attempt to treat people with heart disease at any age - for example those suffering from heart failure - using regenerative medicine".
Comment: In developed countries, though CHD is a leading cause of death among babies and young children, most receive appropriate treatment and survive into adulthood. In this case, understanding any genetic causes becomes important for predicting the risk of recurrence in any offspring they may have. In lower-income countries, however, congenital heart abnormalities result in much higher rates of death and disability; this is one of the problems that the PHG Foundation is addressing by sharing a Toolkit for Congenital Disorders that helps countries assess needs and plan services (see previous news).