Variants in the tau gene (MAPT) region are associated with breast cancer in women and Alzheimer’s disease (AD) among persons lacking apolipoprotein E ε4 (ε4–).
To identify novel genes associated with tau-related pathology, we conducted two genome-wide association studies (GWAS) for AD, one among 10,340 ε4– women in the Alzheimer’s Disease Genetics Consortium (ADGC) and another in 31 members (22 women) of a consanguineous Hutterite kindred.
We identified novel associations of AD with MGMT variants in the ADGC (rs12775171, odds ratio [OR] = 1.4, P = 4.9 × 10–8) and Hutterite (rs12256016 and rs2803456, OR = 2.0, P = 1.9 × 10–14) datasets. Multi-omics analyses showed that the most significant and largest number of associations among the single nucleotide polymorphisms (SNPs), DNA-methylated CpGs, MGMT expression, and AD-related neuropathological traits were observed among women. Furthermore, promoter capture Hi-C analyses revealed long-range interactions of the MGMT promoter with MGMT SNPs and CpG sites.
These findings suggest that epigenetically regulated MGMT expression is involved in AD pathogenesis, especially in women.