Apolipoprotein E genotype and Alzheimer's disease in an elderly Norwegian cohort.

Abstract Apolipoprotein E (Apo E) genotyping was performed on an autopsy cohort of neuropathologically verified non-demented controls and subjects with Alzheimer's disease (AD) resident in nursing homes in the Oslo area. AD was associated with a significantly increased frequency of the Apo E ϵ4 allele; the frequency of the ϵ2 and ϵ3 alleles was lower in AD but not significantly so. Age at death in the control group and the AD group did not differ significantly; neither did age at death nor age at onset of dementia in AD vary according to Apo E genotype, though tendencies towards an earlier age at death was seen in individuals with ϵ4/4 and earlier age at onset dementia in the presence of an ϵ4 allele and a later age of onset the presence of an ϵ3 allele were seen. Possession of an ϵ2 allele had no effect on age at onset of dementia or age at death. Among the possible genotypes there was a trend towards a progression of earliest onset ϵ4/4, ϵ2/4, ϵ3/4, ϵ3/3, ϵ2/3 latest onset of dementia and longest duration ϵ2/4, ϵ4/4, ϵ3/4, ϵ3/3, ϵ2/3 to shortest duration of dementia.