Evidence of the association of BIN1 and PICALM with the AD risk in contrasting European populations

Recent genome-wide association studies have identified 5 loci (BIN1, CLU, CR1, EXOC3L2, and PICALM) as genetic determinants of Alzheimer's disease (AD). We attempted to confirm the association between these genes and the AD risk in 3 contrasting European populations (from Finland, Italy, and Spain). Because CLU and CR1 had already been analyzed in these populations, we restricted our investigation to BIN1, EXO2CL3, and PICALM. In a total of 2816 AD cases and 2706 controls, we unambiguously replicated the association of rs744373 (for BIN1) and rs541458 (for PICALM) polymorphisms with the AD risk (odds ratio [OR] = 1.26, 95% confidence interval [CI] [1.15-1.38], p = 2.9 × 10-7, and OR = 0.80, 95% CI [0.74-0.88], p = 4.6 × 10-7, respectively). In a meta-analysis, rs597668 (EXOC3L2) was also associated with the AD risk, albeit to a lesser extent (OR = 1.19, 95% CI [1.06-1.32], p = 2.0 × 10-3). However, this signal did not appear to be independent of APOE. In conclusion, we confirmed that BIN1 and PICALM are genetic determinants of AD, whereas the potential involvement of EXOC3L2 requires further investigation.