Cardiomyopathy in a child with neutropenia and motor delay.

A 17-month boy with history of neutropenia and gross motor regression was found to have cardiomyopathy upon admission. He was diagnosed with Barth syndrome: dilated cardiomyopathy, neutropenia, skeletal myopathy, decreased stature, and 3-methylglutaconic aciduria, confirmed by tafazzin gene deletion. This diagnosis should be considered in boys with unexplained neutropenia.