elastin and Death--Sudden--Cardiac

Supravalvar aortic stenosis (SVAS) is a less common but clinically important form of left ventricular outflow tract obstruction, and commonly associated with Williams syndrome (WS). SVAS outside of WS may also occur sporadically or in a familial form, often with identifiable mutations in the elastin (ELN) gene. While risk of sudden cardiac death in patients with SVAS has been extensively described in the context of WS, less is known about risk in patients with isolated SVAS. We report a case of a nonsyndromic two-year-old boy with evolving manifestations of SVAS who developed sudden cardiac arrest and death during a sedated cardiac magnetic resonance imaging study. A strong family history of SVAS was present and targeted genetic testing identified an ELN gene mutation in the boy's affected father and other paternal relatives. We review risk factors found in the literature for SCA in SVAS patients and utilize this case to raise awareness of the risk of cardiac events in these individuals even in the absence of WS or severe disease. This case also underscores the importance of genetic testing, including targeted panels specifically looking for ELN gene mutations, in all patients with SVAS even in the absence of phenotypic concerns for WS or other genetic syndromes.

Topics: Aortic Stenosis, Supravalvular; Child; Child, Preschool; Death, Sudden, Cardiac; Elastin; Humans; Magnetic Resonance Spectroscopy; Male; Mutation; Williams Syndrome

Topics: Animals; Aortic Diseases; Biomarkers; Collagen; Death, Sudden, Cardiac; Diagnostic Techniques, Cardiovascular; Elastin; Fibrillins; Humans; Microfilament Proteins; Myosin Heavy Chains; Polymerase Chain Reaction

Supravalvular aortic stenosis is associated with the Williams-Beuren syndrome, but it also occurs in a non-syndromatic congenital form. An elastin gene mutation of chromosome 7q11.23 is responsible in both cases. The vascular features are identical. These patients have a higher risk of sudden death, particularly when undergoing diagnostic or surgical procedures. We report the account of a family with a new mutation in the elastin gene. Screening over three generations revealed eight affected individuals. The cardiac and vascular malformations ranged from mild asymptomatic supravalvular aortic stenosis and isolated dysplastic atrioventricular valves to diffuse arterial hypoplasia. Two infants presented arteries affected at multiple locations, including the left coronary artery. Both died of sudden cardiac death and myocardial ischaemia, one while under general anaesthesia for cardiac catheterisation, and the other perioperatively. We discuss the pathophysiological aspects in these patients that deserve consideration before any general anaesthesia is administered.

Topics: Child; Child, Preschool; Death, Sudden, Cardiac; Disease Progression; DNA; Elastin; Exons; Family; Female; Genetic Predisposition to Disease; Heart Defects, Congenital; Humans; Infant; Male; Mutation; Pedigree; Phenotype