Authors: Meera Gangadharan, MD and Prabhat Mishra, MD --Arkansas Children’s Hospital/University of Arkansas for Medical Sciences, Little Rock, AR


A 12-year-old male child with a medical history of proximal muscle weakness, intellectual impairment, and retinitis pigmentosa presents for dental rehabilitation. A transthoracic echocardiogram reveals hypertrophic cardiomyopathy with left ventricular outflow tract obstruction. There is a family history of male relatives with similar symptoms and early death in the second and third decade. What is the MOST likely diagnosis?