In summary, this work provides further evidence that multiple cholinergic nicotinic receptor genes besides CHRNA5-CHRNA3-CHRNB4 on chromosome 15q25 are involved in nicotine dependence risk not only in European-Americans but also in African-Americans. Future work to replicate these different findings in independent African-ancestry samples – and carry out meta-analysis – should improve our understanding and interpretation of these results. Larger sample sizes are needed to test the effect of these variants on smoking risk in other diverse human populations to help confirm and refine these findings.
