About Video

A 23-year-old male presented with ataxia of gait, limb dystonia, mild choreiform movements and dysarthria. Examination revealed severe restriction of ocular movements, especially in the vertical gaze, suggesting supranuclear palsy. The symptoms started at about twelve years of age when he presented with psychosis. What is the diagnosis? Bone marrow examination revealed sea-blue histiocytes and genetic study confirmed mutation in NPC 1 gene on chromosome 18. It is a lysosomal storage disease where there is accumulation of sphingomyelin in cellular lysosomes. Niemann-Pick disease type A starts in infancy while in type B, the presentation is visceral and the mutation in both of them is in SMPD1 gene.