Variation of interleukin 8 − 251 A > T polymorphism in worldwide populations and intra-ethnic differences in Japanese populations

BackgroundInterleukin-8 (IL8) is a member of the family of chemokines. The IL8 gene has polymorphic variations, and the genotype of IL8 − 251 A > T is associated with smoking behavior and cancer progression.MethodIL8 − 251 A > T polymorphism were investigated in Japanese, from 5 different areas, in Ovambo, Turkish, Mongolian and Korean populations by PCR with confronting 2-pair primers (PCR–CTPP) analysis.ResultsA subpopulation analysis of Japan revealed a north-to-south increase in the frequency of the IL8 − 251 T allele. Among the 5 groups, the Japanese showed the highest frequency of mutant allele followed by the Turks. The distribution pattern in the Japanese was different from those of Mongolians and Koreans. In the Ovambo population, no mutant allele homozygote subject was found and the frequency of mutant alleles was the lowest, similar to that in Gambians.ConclusionThe present study is the first to demonstrate the Japan population inter-prefecture differences in IL8 − 251 A > T polymorphism as well as a certain genetic heterogeneity in the worldwide distribution of IL8 − 251 A > T polymorphism. The distribution results may help define the true significance of IL8 − 251 A > T polymorphism as a marker for smoking behavior in populations worldwide.