NPC1 and cerebellar ataxia: Most NPC cases are due to loss of function of NPC1, and consequently, mice with NPC1 deletion (Npc1−/− knockout mice) reproduces many of the deficits seen in NPC patients, including the neurological symptoms, ataxia by 6–7 weeks of age, and reduced maximal life span to about 10–12 weeks (52, 53).