Apolipoprotein E genotype in diverse neurodegenerative disorders

While the apolipoprotein E (ApoE) ϵ4 allele is a recognized risk factor for Alzheimer's disease (AD), an association of ϵ4 with other neurodegenerative diseases (NDs) has not been extensively explored. We examined 51 cases of neuropathologically confirmed ND. After eliminating 18 cases exhibiting pathology sufficient to warrant an additional diagnosis of AD, three disorders characterized by τ‐related cytoskeletal pathology, i.e., Pick's disease, corticobasal degeneration, and progressive supranuclear palsy, showed increased ϵ4 frequencies. Since the number of cases within each category was small, these increased ϵ4 frequencies were not statistically significant. β‐Amyloid (βA4) immunoreactive diffuse plaques were observed in many of these cases. While we cannot eliminate the possibility that these patients were destined to develop AD, these changes may merely reflect an independent association of ϵ4 with amyloid deposition. These preliminary data affirm the need for further study of well‐characterized cases to explore the relationship of ApoE to cytoskeletal pathology and ND.