An infant with Costello syndrome complicated with fatal hypertrophic obstructive cardiomyopathy

We report a 3-month-old girl with Costello syndrome complicating fatal hype rtrophic obstructive cardiomyopathy. She had typical findings of this syndr ome, slight dyspnea and persistent wheezing. Doppler echocardiography revea led asymmetric septal hypertrophy and systolic anterior movement of the ant erior mitral leaflet. There was grade I mitral regurgitation. Although once her heart failure had been controlled medically, she died suddenly followi ng deterioration of her heart condition. Costello syndrome can complicate f atal hypertrophic obstructive cardiomyopathy.