Oculo-neural involvement in an enzymatically proven case of Niemann-Pick disease type B.

Niemann-Pick disease type B was diagnosed clinically and enzymatically in a 4 years old girl presenting with hepatosplenomegaly, diffuse interstitial infiltrations of both lungs on chest roentgenograms, and foam cells in the bone marrow aspirate. Intelligence and neurological examinations were normal. Spingomyelinase activity was almost totally deficient in leukocytes and cultured skin fibroblasts. Unexpectedly, fundoscopy revealed oculo-neural involvement with a reddish-brown spot of the macula comparable to but differing in some respects from the classic cherry-red spot found in neurolipidoses. By definition patients with type B Niemann-Pick disease should have no cerebral or oculo-neural involvement. Two comparable cases have been described in the literature. The prognosis of this special type is not yet known. For classification--and especially for genetic counselling--it seems important to include the possibility of oculo-neural involvement in the diagnosis of Niemann-Pick disease type B.