Congenital Heart Disease: Molecular Diagnostics of Supravalvular Aortic Stenosis

Supravalvular aortic stenosis (SVAS) is a congenital heart disease that can occur as an isolated autosomal-dominant condition or as part of the developmental disorder Williams-Beuren syndrome (WBS) and is caused by heterozygous genetic lesions involving the elastin (ELN) gene locus on chromosome 7ql 1.23. SVAS is one of many phenotypic features associated with the contiguous gene microdeletion disorder, WBS, and is caused by deletion of the ELN locus on one chromosome 7 homolog. Point mutations, chromosomal deletions, and translocation involving ELN have also been described in individuals with nonsyndromic SVAS. In addition, ELN is involved in the connective tissue disorder, autosomal-dominant cutis laxa, and has been implicated as a susceptibility gene for hypertension and intracranial aneurysms. The molecular analysis of ELN defects is, therefore, an area of significant interest. Genetic screening can be achieved using a variety of techniques to detect both mutations and gross chromosome rearrangements involving the ELN locus, providing the ability to screen families and individuals with SVAS and associated elastinopathies.