Australian researchers are unlocking the code of congenital heart disease

One in every 100 babies is born with a congenital heart disease (CHD), which is a major cause of death in newborns. Despite this, the genetics of the disease are not well understood, which hinders accurate prenatal genetic testing.

Now, researchers from Monash University have uncovered more than 1,300 genes that are linked to CHD, included some that were previously unknown. This may help improve prenatal genetic testing for foetuses.

“[Previous methods] focused on screening genes that are present in the heart only – an approach that often overlooks genes that are present in other tissues as well, despite still playing important roles in heart development,” says Dr Hieu Nim from Australian Regenerative Medicine Institute, the first author of the study, published in Genome Biology, the team expanded the repertoire of genes that are potentially at play in heart development and/or CHD.

“These could comprise many of the missing congenital heart disease genes, but have been, to date, discounted because they are not unique to the heart,” says Associate Professor Mirana Ramialison, also of Monash University’s Australian Regenerative Medicine Institute and the Murdoch Children’s Research Institute.

Once the gene repertoire had been identified, the team used the fruit fly – a well-established model organism in biology – to determine the impact of the novel genes. This is because 75% of the disease-causing genes in humans are also found in a similar form in the fruit fly, so we can get a quick snapshot of the consequences of mutated genes.

The fruit fly experiments revealed “a long list of high-quality candidate genes for causing heart abnormalities in humans, giving real insight into just how susceptible this organ is to genetic mutations,” says Dr Travis Johnson from Monash University’s School of Biological Sciences.

Understanding genetic screening and disease is incredibly complex, so Johnson cautions that the new information isn’t ready for use yet in prenatal genetic screening for CHD.

“We now need to conduct functional studies on all of these genes in animal experiments to determine what they actually do, so its early days,” he explains. “But we now have an excellent starting point.”