Circ Genom Precis Med 2018 03;11(3):e001978
From the Victor Chang Cardiac Research Institute, Sydney, New South Wales, Australia (J.O.S., H.C., D.T.H., E.I., E.G., D.B.S., J.W.K.H., R.M.G., G.C., S.L.D.); Faculty of Science (J.O.S., S.L.D.) and Faculty of Medicine (H.C., D.T.H., E.I., E.G., D.B.S., J.W.K.H., R.M.G., G.C., S.L.D.), University of New South Wales, Sydney, New South Wales, Australia, Sydney, New South Wales, Australia; Children's Hospital at Westmead, Heart Centre for Children (G.M.B., G.F.S., D.S.W.), Sydney, New South Wales, Australia; Sydney Medical School, University of Sydney, New South Wales, Australia (G.M.B., G.F.S., D.S.W.); Genetic Services of Western Australia, Perth (K.H., N.P.); Sydney Children's Hospitals Network, New South Wales, Australia (G.F.S.); Institute of Health and Biomedical Innovation, Queensland University of Technology (P.L., E.L.D.); Department of Endocrinology and Diabetes, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia (E.L.D.); University of Queensland, Brisbane (E.L.D.); and School of Paediatrics and Child Health, University of Western Australia, Perth, Western Australia, Australia (N.P.).
Background: Congenital heart disease (CHD)-structural abnormalities of the heart that arise during embryonic development-is the most common inborn malformation, affecting ≤1% of the population. However, currently, only a minority of cases can be explained by genetic abnormalities. The goal of this study was to identify disease-causal genetic variants in 30 families affected by CHD.
Methods: Whole-exome sequencing was performed with the DNA of multiple family members. We utilized a 2-tiered whole-exome variant screening and interpretation procedure. First, we manually curated a high-confidence list of 90 genes known to cause CHD in humans, identified predicted damaging variants in genes on this list, and rated their pathogenicity using American College of Medical Genetics and Genomics-Association for Molecular Pathology guidelines.
Results: In 3 families (10%), we found pathogenic variants in known CHD genes , , and , explaining the cardiac lesions. Second, exomes were comprehensively analyzed to identify additional predicted damaging variants that segregate with disease in CHD candidate genes. In 10 additional families (33%), likely disease-causal variants were uncovered in , , , , , , , , , , and .
Conclusions: The pathogenesis of CHD could be explained using our high-confidence CHD gene list for variant filtering in a subset of cases. Furthermore, our unbiased screening procedure of family exomes implicates additional genes and variants in the pathogenesis of CHD, which suggest themselves for functional validation. This 2-tiered approach provides a means of (1) identifying clinically actionable variants and (2) identifying additional disease-causal genes, both of which are essential for improving the molecular diagnosis of CHD.