Allele and genotype frequencies at the APOE locus in necropsy confirmed AD cases and non-demented elderly controls. APOE alleles were differently distributed in cases and controls (χ2 2=78, p<0.001). APOE ε4 carriers had an odds ratio for disease of 4.87 (95% CI 3.38–7.01, χ2 1=77, p<0.001) compared to non-carriers. Genotype frequencies were significantly different in cases v controls (χ2 5=94, p<0.001)
| Controls | % | Cases | % | Odds ratios with 95% CI | |
| Allele ε2 | 70 | 10 | 15 | 3 | 0.36 (0.20–0.64) |
| Allele ε3 | 537 | 79 | 318 | 67 | 1 |
| Allele ε4 | 77 | 11 | 145 | 30 | 3.18 (2.33–4.33) |
| Total | 684 | 100 | 478 | 100 | |
| Genotype ε2/2 | 1 | 0.3 | 1 | 0.4 | 2.20 (0.13–35.47) |
| Genotype ε2/3 | 56 | 16 | 6 | 3 | 0.24 (0.10–0.56) |
| Genotype ε2/4 | 12 | 4 | 7 | 3 | 1.28 (0.50–3.35) |
| Genotype ε3/3 | 213 | 62 | 97 | 41 | 1 |
| Genotype ε3/4 | 55 | 16 | 118 | 49 | 4.71 (3.16–7.03) |
| Genotype ε4/4 | 5 | 1 | 10 | 4 | 4.39 (1.46–13.19) |
| Total | 342 | 100 | 239 | 100 |