To interrogate a poly-T variant (rs10524523, '523) in <i>TOMM40</i>, a gene adjacent to the <i>APOE</i> gene on chromosome 19, in older persons with <i>APOE</i> ε3/3 homozygosity for association with cognitive decline, the clinical hallmark of Alzheimer disease (AD).
The very long (VL) poly-T variant at rs10524523 ("523") of the TOMM40 gene may hasten the onset of late-onset Alzheimer's disease (LOAD) and induce more profound cognitive impairment compared with the short (S) poly-T variant.
The minor allele of rs4420638 (G) and the minor allele of rs157582 (T) showed associations with lower Mini-mental State Examination score, higher Alzheimer Disease Assessment Scale-cognitive subscale 11 score and smaller entorhinal volume using both baseline and longitudinal measurements, as well as with accelerated cognitive decline.
We found 2 independent associations among European-Americans in the 19q13.32 region: rs769449 (APOE intron; p = 3.1 × 10(-20)) and rs115881343 (TOMM40 intron; p = 6.6 × 10(-11)). rs769449 was also associated with cognitive decline among African-Americans (p = 0.005), but rs115881343 was not.
Our prevalent case study comparing prevalent AD cases (n = 428) with participants with no cognitive impairment (n = 524) revealed a significant association of rs6656401 and rs3818361 (CR1), rs2075650 (TOMM40), rs7561528 (BIN1), and rs3865444 (CD33) with late-onset AD that were robust to adjustment with age and apolipoprotein E ε4 genotype.