Niemann-Pick type C disease:: Accelerated neurofibrillary tangle formation and amyloid β deposition associated with apolipoprotein E ε4 homozygosity

Niemann-Pick type C disease is a neurovisceral storage disorder. Neurofibrillary tangles similar to those in Alzheimer's disease have been reported in most juvenile/ adult patients without amyloid P protein (Abeta) deposits. Recently, we found deposits of Abeta in the form of diffuse plaques in three (31- and 32-year-old sisters and a 37-year-old man) of nine Niemann-Pick type C disease patients, who presented with most severe tauopathy and with numerous neurofibrillary tangles. Abeta deposits were not detected in any of the control brains of patients younger than age 42 years. These three patients with Abeta deposit all were homozygotes of apolipoprotein E epsilon-4. Our study suggested that NPC1 gene mutations combined with homozygosity of apolipoprotein E epsilon4 alleles could manifest neuropathology similar to that of Alzheimer's disease. Investigation of these patients may provide an important due for understanding the pathogenesis of Alzheimer's disease.