Although rs16969968 is in the coding sequence of CHRNA5, and a biologically plausible relationship exists between CHRNA5 and nicotine dependence, SNPs in high LD with rs16969968 span a large area encompassing the genes IREB2, PSMA4, CHRNA5, CHRNA3, and CHRNB4. Although rs16969968 is a compelling candidate for a causal association with nicotine dependence, other unidentified but related markers cannot be excluded as the cause for the observed association with nicotine dependence.
