The absence of replication of findings for rs10482672 in the African-American sample may be an artifact of differences in the genomes of African-American and European-American children in the Fast Track sample. We used a tagging SNP approach to measure variation in NR3C1. (Instead of identifying variants in the gene that were likely to cause differences in intervention effects, we instead identified variants that provided a parsimonious summary of all variation in NR3C1.) African-descent populations are more genetically diverse than European-descent populations and there is less linkage in African-descent as compared to European-descent genomes. These differences could have the result that our SNP set was a less comprehensive measure of NR3C1 variation for the African-American children as compared to the European-American children. Therefore, the possible causal variant that was measured with rs10482672 in the European-American sample might have gone unmeasured in the African-American sample.
