In this study, we leveraged gene variants associating with PD to search for variants that associate with AD. We found a gene variant that was in strong LD with markers in the MAPT gene on chromosome 17 and that was previously associated with PD. This SNP was significantly associated with longitudinal atrophy of the entorhinal cortex and hippocampus and demonstrated a strong association with MAPT transcript levels within the brain. Considered together, our findings point to the tau-associated MAPT locus as a site genetic overlap between AD and PD.
