Clinical and biochemical study of a child with the non-neuronopathic-Type B form of Niemann-Pick disease.

A child with Niemann-Pick disease type B, diagnosed at the age of two years and followed up for three years is described. Despite extensive visceral involvement--as deduced from marked hepatosplenomegaly and pulmonary infiltration--the child is in general good health and has no apparent neurologic abnormality. Biochemical studies revealed a tenfold increase of sphingomyelin content in his liver biopsy specimen and a markedly reduced sphingomyelinase activity in peripheral blood leukocytes. His parents were found to be heterozygous carriers of the disease, showing sphingomyelinase activity values intermediate between those of patient and healthy subjects. The relevant literature, concerning patients with the non-neuronopathic type B form, is reviewed.