APOE Alleles with Tau and Aβ Pathology in Patients with Amyotrophic Lateral Sclerosis and Parkinsonism-Dementia Complex in the Kii Peninsula

Background and ObjectivesTo examine the association of the APOE ϵ4 and ϵ2 alleles with the pathologic features of patients with amyotrophic lateral sclerosis and parkinsonism-dementia complex cases in the Kii peninsula of Japan (Kii ALS/PDC).MethodsWe analyzed APOE variants in 18 autopsy patients with ALS/PDC, consisting of 9, 8, and 1 patient with PDC, ALS, and PDC followed by ALS, respectively. Moreover, we revealed the relationship between APOE variants and Aβ and tau pathologies.ResultsThe frequency of the ϵ4 allele was not different between patients with Kii ALS/PDC and control participants. APOE ϵ4 was associated with increased Aβ pathology (p = 0.005 by the χ2 test), but not with increased tau pathology (p = 0.984). The frequency of the ϵ2 allele was apparently higher than that of control participants (p = 0.254). The APOE ϵ2 allele was associated with increased tau pathology (p = 0.009) and not with reduced Aβ pathology (p = 0.383) in patients with Kii ALS/PDC.DiscussionAlthough there was no overrepresentation of the frequency of the ϵ4 or ϵ2 allele, our findings suggest that the ϵ2 allele is associated with increased tau pathology and not with reduced Aβ pathology in patients with Kii ALS/PDC.