In single-SNP based tests, AD risk allele of APOE (rs2075650) was associated with smaller HV (p = 0.0054) and CD33 (rs3865444) with smaller intracranial volume (p = 0.0058).
Overrepresentation of glutamate signaling in Alzheimer's disease: network-based pathway enrichment using meta-analysis of genome-wide association studies.
Recently, the rs2075650 single nucleotide polymorphism in the translocase of outer mitochondrial membrane 40 homolog (TOMM40) gene was identified as a risk factor for AMD and Alzheimer disease.
Three SNPs [rs429358 in APOE: odds ratio (OR)=4.24, 95% confidence interval (CI)=3.01-5.96, P=1.23×10; rs2075650 in APOE: OR=3.57, 95% CI=2.51-5.06, P=1.23×10; and rs677909 in PICALM: OR=0.63, 95% CI=0.49-0.81, P=0.00036, log additive model] were significantly associated with AD susceptibility after correction for multiple testing.
There were four significant associations between genotypes and phenotypes of AD patients: CR1 SNP rs11803956 correlated with Mini-Mental State Examination (MMSE) score (β=1.718, Pcorrected=0.002); ABCA7 SNP rs3752232 correlated with Rey Complex Figure Test (RCFT) copy score (β=-6.861, Pcorrected=0.013); APOE SNP rs2075650 correlated with the percentile of RCFT copy score (β=14.005, Pcorrected=0.021) and the percentile of total score in phonemic fluency (β=11.052, Pcorrected=0.035).
The AA genotype of the aging-related single-nucleotide polymorphism (SNP) rs2075650 in TOMM40 has been associated with longevity, while the AG and GG genotypes are associated with an increased risk of Alzheimer's disease.
Alleles A of CD33 rs3865444 and A of TOMM40 rs157580 were both protective factors for AD onset (OR=0.94, 95% CI: 0.90-0.98, P value=0.003; OR=0.62, 95% CI: 0.57-0.66, P value <0.001).