The strong concordance between CHRNA5 differential allele expression and heterozygosity detected in this study suggests that one or more of the 6 SNPs (rs1979907, rs1979906, rs1979905, rs880395, rs905740, and rs7164030), in a single LD bin (with r2≥0.94, D′ = 1 in populations of both African and European ancestry) spanning ∼2.5 kb at the 5′ distal region of the CHRNA5 transcript are potential causal variants that alter the mRNA expression of this gene. This study reinforces previous findings that these 6 variants account for allelic expression differences in overall CHRNA5 mRNA expression in human frontal cortices [23] and possibly in the human amygdala and nucleus accumbens [25].
