Niemann-Pick type C is an autosomal recessive lipid storage disease caused by mutations in the NPC1 or NPC2 gene. In childhood-onset Niemann-Pick type C, the usual course is slowly progressive, with normal cerebral magnetic resonance at onset. Here the authors present the case of a patient carrying 2 compound heterozygous NPC1 mutations: the known nonsense mutation (p.Trp833X) in exon 16 and a novel missense mutation (p.Ile609Phe) in exon 12. At onset, the patient presented ataxia, cognitive decline, and epilepsy, with early cerebral atrophy and marked cerebellar vermis atrophy. The course of the disease was rapid, and the patient died within 1-2 years of onset. A possible phenotype-genotype correlation is discussed. This case further expands the clinical spectrum and the genetic heterogeneity of Niemann-Pick type C due to NPC1 mutations.
Keywords: Niemann-Pick type C1; compound heterozygote; early cerebellar atrophy; severe course.