Congenital heart defects (CHDs) are the most common serious birth defect and a leading cause of infant mortality. Affected individuals who survive infancy require substantial medical care and experience lifelong morbidity and early mortality. Despite their prevalence and impact upon public health, the etiology of CHDs is poorly understood. Our long-term goal is to better define the genetic basis of CHDs and using this information, develop preventive measures and provide precise medical management based on genotype. As CHDs are a heterogeneous group of conditions, we have focused our studies on cases with conotruncal heart defects (CTDs) that comprise at least 36% of all CHDs and are a prominent feature of the 22q11.2 deletion syndrome (22q11DS). We have conducted both SNP- and CNV-based genome-wide association studies as part of our previous and current P01 (HD070454). Our current analyses of genes and gene-sets provide new insights regarding the contribution of common and rare inherited genetic variants to CTDs. Specifically, based on the results from our studies as well as recently published findings, we hypothesize that: (1) CTDs are influenced by the full range of genetic variability (rare to common; de novo and inherited) in relevant gene-sets; (2) the number of disease-related variants within these gene-sets varies directly with CTD severity; and (3) gene-sets associated with CTDs in nonsyndromic individuals are also associated with CTDs in individuals with the 22q11DS. To augment our existing cohorts and thus substantially improve the statistical power of our proposed analyses, application was made to complete array genotyping of a set of patients with CTDs and in particular, those with mild disease represented by isolated aortic arch anomalies. The new cases with CTD and some with an isolated aortic arch anomaly were ascertained at the Children's Hospital of Philadelphia (CHOP) while some of the cases with isolated aortic arch anomalies were ascertained by the <a href="https://www.ncbi.nlm.nih.gov/projects/gap/cgi-bin/study.cgi?study_id=phs001194">Pediatric Cardiac Genomics Consortium (PCGC)</a>. A small group of cases with left-sided obstructive lesions from CHOP were included to combine with our existing datasets to serve as a comparison to those with CTD. The additional genotype data will augment the statistical power of the proposed common variant analyses. We anticipate that this work will reduce the gaps in our understanding of CTDs by identifying an explicit set of genes associated with CTD-risk by way of common variants. This work will also help define the genetic architecture for the full clinical spectrum of these common birth defects.

Genes for Non-Syndromic Congenital Heart Disease

The Congenital Heart Disease Genetic Network Study: Rationale, Design, and Early Results

Genome-Wide Association Studies and Meta-Analyses for Congenital Heart Defects

Genome-wide association study of maternal and inherited effects on left-sided cardiac malformations.