The major Alzheimer's disease susceptibility genes (APOE, clusterin, complement receptor 1 (CR1) and phosphatidylinositol binding clathrin assembly protein, PICALM) can be implicated directly (APOE, CR1) or indirectly (clusterin and PICALM) in the herpes simplex life cycle.
A recent large genome-wide association study (GWAS) has identified significant association of two single nucleotide polymorphisms (SNPs) (rs6656401 and rs3818361) in the CR1 gene with AD in Caucasians.
To determine whether genetic variants in CLU, CR1, and PICALM confer risk for AD in independent data sets (n = 4254) and to test the impact of these markers on cerebrospinal fluid (CSF)-Aβ42 and total-tau protein levels (n = 425).
How precisely the different functional role of CR1-S in the immune complement cascade contributes to AD pathogenesis will need additional functional studies.
Accumulated evidence suggests that a variant within the CR1 gene (single nucleotide polymorphism rs6656401), known to increase risk for Alzheimer disease (AD), influences β-amyloid (Aβ) deposition in brain tissue.
Here, we show that two Alzheimer's disease-associated CR1 variants, rs6656401 and rs3818361, are associated with major recurrent depression in females in a population-based cohort using individuals from the Generation Scotland: Scottish Family Health Study.
Using 1709 subjects (697 deceased) from the Religious Orders Study and the Rush Memory and Aging Project, we tested 41 single-nucleotide polymorphisms (SNPs) within the linkage disequilibrium block containing the published CR1AD SNP (rs6656401) for associations with episodic memory decline, and then examined the functional consequences of the top result.
We investigated the influence of the rs6656401 single nucleotide polymorphisms (SNP) of the CR1 gene, the rs3851179 SNP of the PICALM gene, and the rs11136000 SNP of the CLU gene on risk of AD in a Polish population.
These findings question a role for the Ser1610Thr variant in AD risk and related endophenotypes, and reaffirm our previous observation that the CR1 CNV could be the true functional risk factor explaining the association between CR1 and AD.
These observations indicate that AD susceptibility is associated with the long CR1 isoform (CR1*2), albeit at a lower density, suggesting that AD results from insufficient clearance of plaque deposits rather than increased inflammation.
Single nucleotide polymorphisms (SNPs) in and near ABCA7, BIN1, CASS4, CD2AP, CD33, CELF1, CLU, complement receptor 1 (CR1), EPHA1, EXOC3L2, FERMT2, HLA cluster (DRB5-DQA), INPP5D, MEF2C, MS4A cluster (MS4A3-MS4A6E), NME8, PICALM, PTK2B, SLC24A4, SORL1, and ZCWPW1 have been associated with Alzheimer's disease (AD) in large meta-analyses.