There is only one prior study directly reporting an association between CD and an (AAT)n polymorphism in CNR1, a population-based association study conducted in a male African Caribbean sample (Ballon et al 2006). African Caribbeans are an admixed population (Benn-Torres et al 2008) and allele frequencies of CNR1 variants differ among different ancestral populations (Covault et al 2001; Herman et al 2006; Zhang et al 2004). Although an adjustment for admixture effects is required to avoid potential spurious associations, it was not included in that study. The (AAT)n polymorphism is located between SNP9 and SNP10, 7kb away from SNP10. SNP10 showed nominal association with CIP in the EA family sample in the present study. Thus, further work is warranted to investigate the association between this locus and CD.
