Contributor: Gordon K. Klintworth
Niemann-Pick disease type A (classical infantile Niemann-Pick disease) is one variant of Niemann-Pick disease according to the past Crocker classification. Currently these patients would be classified as having Niemann-Pick disease type I. Niemann-Pick disease type A, the most common and severe type of Niemann-Pick disease, is due to a deficiency of  sphingomyelinase. Many of these patients are of Eastern European Jewish ancestry and affected individuals present in infancy with hepatosplenomegaly and a rapidly progressive deterioration in central nervous system function. Other features are lymphadenopathy and a yellow-brown discoloration of the skin. Corneal opacification and a cherry red spot at the macula are ophthalmic manifestations. Death is usually <4 years of age.