Congenital Heart Disease Breakthrough

Institute plays vital role in exciting new research into congenital heart disease led by the University of Oxford

9 June 2021

Congenital Heart Disease (CHD) is the most common human birth defect that globally affects nine in every 1,000 live births. It is a major cause of infant mortality and can require ongoing medical treatment. Yet, despite the prevalence of the condition, the cause of the vast majority of cases remains unknown.

Now, a team at the University of Oxford has identified an entirely new risk factor for causing CHD.

Using an animal model system, researchers have shown that if the mother is severely iron deficient and anaemic during early pregnancy, this greatly increases the risk that her offspring will have heart defects.

The results published in Nature Communications have also shown that the risk of CHD can be greatly reduced if the mother is given iron supplements, provided this happens very early in pregnancy before the heart has formed in the embryo.

The Institute's role in the CHD Research

Associate Professor Duncan Sparrow from the University of Oxford was the lead researcher in the study, but the Victor Chang Cardiac Research Institute’s Associate Professor Eleni Giannoulatou played an integral role in the findings by analysing the genetic data collected from the embryos.

A/Prof Giannoulatou, who runs the Computational Genomics Laboratory at the Institute, studied the vast data set produced from a technique called transcriptomics and discovered which genes were involved in the heart defect formation and when they were being switched on during pregnancy.

She compared 20,000 genes across normal embryos and iron-deficient embryos at a time during pregnancy when the heart is forming in the embryo. Crucially, she identified the genes that were causing the heart defects in the iron-deficient embryos.

A/Prof Giannoulatou said: “Our work identified the mechanism of how this takes place and what genes were involved in the process. It was an incredible moment when after months of work we were able to make this discovery and share the findings.”

Using the latest next-generation sequencing technologies, the Computational Genomics Laboratory develops techniques to speed up the analysis of massive sequencing datasets – information taken from patient DNA - to identify mutations that cause different types of heart disease.

A/Prof Sparrow, who worked at the Victor Chang Cardiac Research Institute for 15 years until 2015, says the work A/Prof Giannoulatou contributed was critical to his findings.

“These are vast data sets which require incredibly complex analysis. But Eleni was able to identify exactly what was going wrong in these embryos. And in technical terms she revealed that a subset of cardiac stem cells stopped dividing and turned into heart cells too early,” says A/Prof Sparrow.

The University of Oxford research team hope their findings, if applicable to humans, can be translated to clinical practice to ultimately reduce the birth prevalence of CHD worldwide.

This is not the first time A/Prof Giannoulatou has played a key role in an innovative discovery.

Her work underpins ground-breaking efforts pioneered by the Institute’s Professor Sally Dunwoodie on CHD and Professor Bob Graham on spontaneous coronary artery dissection (SCAD).

A/Prof Giannoulatou says: “We analyse DNA data to find mutations that cause disease. We're looking at millions and millions of genetic variants to identify a single mutation that could be the cause of disease. My group develops new methods to improve this analysis and ultimately increase the genetic diagnostic rate.”

Note

The full paper “Maternal iron deficiency perturbs embryonic cardiovascular development in mice” (Kalisch-Smith el al 2021) can be read in Nature Communications.

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For all media enquiries and interview requests, please contact:

Julia Timms
Head, Media & Communications
j.timms@victorchang.edu.au
0457 517 355