A neonate with supravalvular aortic stenosis is associated with which syndrome?

• A. Noonan syndrome
• B. Williams syndrome
• C. Turner syndrome
• D. Marfan syndrome

Answer: (B)

Supravalvular aortic stenosis in a newborn is a hallmark finding of Williams syndrome. This condition results from deletion of the elastin gene (ELN) on chromosome 7q11.23, causing elastin haploinsufficiency in the arterial walls. The reduced elastin leads to arteriopathy with narrowing just above the aortic valve, producing SVAS. Recognizing SVAS in a neonate thus strongly points to Williams syndrome, and prompts genetic testing for ELN deletion.

Other syndromes have different cardiovascular patterns that don’t center on SVAS. Noonan syndrome more commonly features pulmonary valve stenosis or hypertrophic cardiomyopathy; Turner syndrome often presents with coarctation of the aorta; Marfan syndrome typically involves aortic root dilation and dissection rather than SVAS.