An inherited (autosomal recessive) disorder of lipid metabolism due to a defect in the enzyme sphingomyelinase and resulting in accumulation of sphingomyelin (a sphingolipid) and other phospholipids in the bone marrow, brain, liver, and spleen. Patients present with neurological problems, mental retardation, and enlargement of the liver and spleen at a young age. There are four known types of the disease. A. Niemann (1880–1921), German paediatrician; L. Pick (1868–1944), German pathologist
Subjects: Medicine and Health — Genetics and Genomics.