Association of Parkinson's Disease GWAS-Linked Loci with Alzheimer's Disease in Han Chinese

Alzheimer's disease (AD) and Parkinson's disease (PD) have overlapping pathological mechanisms and genetic background, suggesting it would be meaningful to replicate PD-related genetic variants in AD population to identify new loci of AD. Here, in order to discover potential AD-related loci, we investigated the association between late-onset AD (LOAD) susceptibility and nine single-nucleotide polymorphisms (SNPs) (rs11724635 of BST1, rs12637471 of MCCC1, rs15553999 of TMEM229, rs17649553 of MAPT, rs34311866 of TMEM175-GAK-DGKQ, rs356182 of SNCA, rs6430538 of ACMSD-TMEM163, rs76904798 of LRRK2 and rs823118 of RAB7L1-NUCKS1) which were reported to have genome-wide significant associations with PD risk in a recent Genome Wide Association Study performed among white population. We included 2350 samples comprising with 992 sporadic LOAD patients and 1358 gender- and age-matched control subjects who were unrelated northern Han Chinese residents. Finally, among these included genetic variants, only rs76904798 of LRRK2 was proved to significantly reduce LOAD risk in a multivariate analysis in a dominant model after adjusting for age, sex, and apolipoprotein E (APOE) epsilon 4 status (OR = 0.616; 95 % CI 0.446-0.849; Bonferroni corrected P = 0.027). In addition, when these data were stratified by APOE epsilon 4 status, rs76904798 was still evident among subjects without APOE epsilon 4 allele. Our results first time indicated rs76904798 of LRRK2 is also a common risk genetic variant for LOAD susceptibility in a northern Han Chinese people.