| Niemann-Pick disease | <disease> A family of severe lysosomal storage diseases resulting in an accumulation of sphingomyelin and other phospholipids in the reticuloendothelial system. The best studied forms are due to deficiency of sphingomyelinase and it is more common in Ashkenazi Jews than other groups. Clinical signs include foam cells in the blood and marrow, hepatosplenomegaly and neurologic degeneration. Diagnosis is confirmed by enzyme assay on leukocytes or fibroblasts and specific mutations in the gene are now recognised. (29 Dec 1997) |
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| disease, pick's | A form of dementia characterised by a slowly progressive deterioration of social skills and changes in personality leading to impairment of intellect, memory, and language. (12 Dec 1998) |