Abstract
The apolipoprotein E (Apo E) phenotype of 32 individuals at least 100 years of age was determined by isoelectric focusing and Western blotting. Among them, 21 persons (65.6%) did not exhibit dementia, while 11 persons (34.4%) had Alzheimer's disease (AD), the onset of which occurred 97.5 years previously on average. The proportion of Apo E3/3 and E3/4 in patients with AD was 90.9% and 9.1%, respectively, and no other phenotype was detected. This proportion was not significantly different from that of non-demented persons. This finding suggests that the phenotype of Apo E is not related to the risk of AD in persons of very advanced age. Genetic analysis revealed that the involvement of the ε2 and ε4 alleles in very advanced aged AD patients is not likely because the ε2 allele was not detected. We concluded that inheritance of the ε4 allele of Apo E is not a risk factor for AD in the very old population.
