The lifespan of patients with NPC is usually related to the age of onset. Children with antenatal or infantile onset usually succumb in the first few months or years of life, whereas adolescent and adult onset forms of Niemann–Pick<unk>  C have a more insidious onset and slower progression, and affected individuals may survive to the seventh decade. Adult cases of NPC are being recognized with increasing frequency. It is suspected that many patients affected by NPC are undiagnosed, owing to lack of awareness of the<unk>  and the absence of readily available screening or diagnostic tests. For the same reasons the diagnosis is often delayed by many years.
Niemann–Pick disease, type C
Niemann–Pick disease, SMPD1-associated
Wilson–Mikity syndrome
Haemochromatosis type 3
Hemochromatosis type 4
Wilson's disease
Mowat–Wilson syndrome
Bannayan–Riley–Ruvalcaba syndrome