Association of apolipoprotein E4 with sporadic Alzheimer's disease is more pronounced in early onset type

Abstract

Apolipoprotein E genotypes in 88 unrelated Japanese patients with NINCDS-ADRDA sporadic Alzheimer's disease (AD) were examined and compared with those of 93 healthy controls. Frequency of ε4 allele was increased in patients with AD (31%) compared with controls (10%), as was reported previously. Individuals homozygous or heterozygous for the allele ε4 had a 5.9-fold increased risk of AD. This tendency was more pronounced in early onset sporadic (= non-familial) type than late onset type. The relative risk was also greater for early onset type (RR = 11.7; 95% CI, 4.9–28.3) and late onset type (RR = 4.3; 95% CI, 2.1–8.8). Moreover, patients with homozygote for the allele ε4 had a 14.7-fold increased risk of early onset sporadic AD ( P<0.005, X 2 = 9.0, df = 1, 95% CI, 2.5–85.1). Our findings indicated that association of apolipoprotein ε4 with sporadic Alzheimer's disease is more pronounced in early onset type than in late onset type.