Williams syndrome (WS) is characterized by a range of clinical features, including cardiovascular disease, distinctive facial traits, neurobehavioral disorders, and a condition known as transient infantile hypercalcemia. Among these, endocardial calcification represents a non-specific response to severe, etiologically diverse myocardial injuries. In this report, we document a unique case involving an infant with WS who exhibited rapidly progressive arterial stenosis and left ventricular endocardial calcification, associated with a novel heterozygous deletion. While arterial stenosis is the most frequently observed cardiovascular issue in WS, instances of endocardial calcification during infancy are exceedingly rare and have not previously been reported in the context of WS.

Massive endocardial calcification is a rare entity. We describe a rare disease endomyocardial fibrosis associated with massive calcification of the left ventricle suspected on a chest X-ray and confirmed by echocardiography and computed tomography in an 18-year-old female presenting with breathlessness and congestive heart failure.