Distribution characteristics of polymorphisms of interleukin-22 gene in Guangxi population and their association with serum lipid levels

AIM: To investigate the distribution characteristics of interleukin-22 (IL-22) gene rs2227485C/T and rs2227491A/G polymorphisms in Guangxi people and the distribution differences with other ethnic groups, and to explore the difference levels of common lipid indexes in different genotypes. METHODS: SNaPshot technique and DNA sequencing were used in 280 Guangxi persons to examine IL-22 genotypes and to analyzed the distribution frequencies of allele and genotype in these sites. The distribution frequencies in different sexes, and the differences between groups and diffe-rence levels of common lipid indexes in different genotypes were analyzed statistically. RESULTS: Three genotypes of CC, CT and TT were found in rs2227485C/T with the frequency distribution of 17.1%, 49.3% and 33.6%, respectively. No significant difference between different sexes of each genotype and allele frequency in the Guangxi population was observed (P>0.05). Compared with the distribution frequencies of genotype and allele in HapMap-TSI, HapMap-HCB, HapMap-JPT and HapMap-MEX, those in Guangxi population showed statistically significant differences (P<0.05). Three genotypes of AA, AG and GG were found in rs2227491A/G with the frequency distribution of 16.1%, 52.8% and 31.1%, respectively. There was no significant difference between different sexes of each genotype and allele frequency in the Guangxi population (P>0.05). The significant differences of genotype frequencies among Guangxi population, HapMap-TSI, HapMap-JPT and HapMap-MEX were detected (P<0.05). Compared with the other 4 populations, allele frequencies in Guangxi population had significant difference (P <0.05). There were significant differences in the levels of HDL-C and LDL-C among the 3 genotypes of rs2227491A/G. The level of HDL-C had difference between AG/AA genotype and GG genotype. In addition, the level of LDL-C had difference between AG/GG genotype and AA genotype (P<0.05). CONCLUSION: rs2227485C/T and rs2227491A/G polymorphisms of IL-22 gene have differences in different populations. The rs2227491A/G polymorphism may be associated with serum lipid levels.