Lastly, an association seen in one population that is not consistent across all three may nonetheless represent a true biological signal. Lack of consistency for the association may simply reflect differences in power for our population samples. Issues that can affect power across our three diverse populations include sample size, minor allele frequency, and even population-specific effect size. The last factor could arise in a variety of ways, including differences in LD structure, background variation, and marker information content. Thus we suggest caution when interpreting the negative or non-consistent association results from this study. Though these results strengthen the evidence for rs16969968 as a likely causal variant, this region remains in need of further interrogation with additional genotyping and standardized imputation across all populations.
