CYP19A1 and Alzheimer disease: 4 SNPs in CYP19 were correlated with 2-fold increase risk for AD with 3 only significant individuals without an APOE ε4 allele.4 SNPs in CYP17 were linked with a 2.5-fold increased risk for AD, which was independent of APOE genotype.Individuals carrying high risk alleles in both CYP17 and CYP19 were associated with ~4-fold elevated risk for AD and increased sex hormone binding globulin in post-menopausal women.Variants in both genes involved in E2 bioavailability was associated with decreased age of AD onset in women with DS.