Genetic Basis of CHD and Management Guide for Specific Diagnostic Tests

Congenital heart disease (CHD) represents one of the most common major congenital anomalies with an incidence of 0.8% of live births. CHD can be a simple lesion, such as an atrial or ventricular septal defect that usually can be repaired relatively easily with one surgical or catheter-based intervention, or it may be a more complex lesion, such as hypoplastic left heart syndrome (HLHS) that would need multiple stages of cardiac surgery as part of the so-called single ventricle palliation pathway. Most of CHDs rarely occur in families; thus identifying their genetic basis can be more challenging and requires several different approaches. Overall, structural CHDs are similarly characterized by marked genetic heterogeneity and complexity, and the evidence of decreased penetrance or variable expressivity suggests that additional environmental factors contribute to the risk of disease as well.