ABSTRACTIntroductionMany Alzheimer’s disease (AD) genetic association studies disregard age or incorrectly account for it, hampering variant discovery.MethodUsing simulated data, we compared the statistical power of several models: logistic regression on AD diagnosis adjusted and not adjusted for age; linear regression on a score integrating case-control status and age; and multivariate Cox regression on age-at-onset. We applied these models to real exome-wide data of 11,127 sequenced individuals (54% cases) and replicated suggestive associations in 21,631 genotype-imputed individuals (51% cases).ResultsModelling variable AD risk across age results in 10-20% statistical power gain compared to logistic regression without age adjustment, while incorrect age adjustment leads to critical power loss. Applying our novel AD-age score and/or Cox regression, we discovered and replicated novel variants associated with AD on KIF21B, USH2A, RAB10, RIN3 and TAOK2 genes.DiscussionOur AD-age score provides a simple means for statistical power gain and is recommended for future AD studies.
Impact of home visit capacity on genetic association studies of late-onset Alzheimer's disease