Niemann-Pick disease is an inherited metabolic disorder where lipids are not able to be metabolized adequately and hence build up and cause damage in various parts of the body such as the spleen, liver, lungs, bone marrow and brain. The different types of the disease are due to different genetic mutations. Type C is a juvenile or subacute form of the condition which usually starts during childhood and survival into adulthood is possible. See also Niemann-Pick disease, type C2