not highly significant. Disequilibrium in patients supports that the gene may be related to AD because the genotype distributions observed differ from those expected by chance; however, disequilibrium in controls is more likely to reflect genotyping error and thus distort the analysis in some degree (Luo et al. 2008). The sixth reason is different statistical power and type II error due to sample size as well as different genotyping methods. In addition, cultural differences may interact with the genetic components and result in differentially significance levels of protection of ALDH2 504lys against AD across different ethnic groups.
