“flipped” findings in CHRNG and CHRNA4 is that these regions are likely to be involved in genetic risk contributing to nicotine dependence, but further genotyping or resequencing is necessary to refine these associations. Although SNPs in this study were selected to tag the common variation in European-Americans, the reduced LD in African-Americans means that more coverage is needed across this diverse sample. After more complete assessment of the genetic variation is obtained, analysis of a diverse sample can leverage LD differences and refine the associations to a smaller group of SNPs that show more consistent effects across populations (Saccone et al., 2008, Zaitlen et al., 2010).
