Atypical Williams syndrome in an infant with complete atrioventricular canal defect.

Williams-Beuren Syndrome (WBS) is a well-described microdeletion syndrome characterized by specific dysmorphic facial features, peripheral pulmonic stenosis, supravalvular aortic stenosis, hypercalcemia, feeding difficulties, gastroesophageal reflux, short stature, and specific intellectual disabilities (such as visual spatial problems). WBS is caused by 7q11.23 deletions that contain multiple genes known to contribute to the above phenotype. We report a neonate with a complete atrioventricular canal (CAVC) defect, an atypical cardiac lesion for WBS, and few typical phenotypic features of WBS, diagnosed at 20 days of life.