Dimorphism -23HphI in the INS gene (rs689): the association with type 1 diabetes mellitus in the populations of the Russian Federation, the inter-population comparison of the frequencies
Objective. The objective of the present study was to elucidate the association between dimorfism -23HphI in the INS gene (rs689) and type 1 diabetes mellitus in several populations of the Russian Federation and to compare the frequency of alleles of this dimorphism in different populations. Material and methods. The case-control association was investigated in five populations of the Russian Federation, viz. Russian, Bashkir, Udmurtian, Yakutian, and Buryat ones. The DNA samples from 528 patients presenting with type 1 diabetes mellitus and 439 control subjects were available for the investigation, Polymorphism typing was performed using the RFLP-PCR technique. The degree of association of the trait of interest with the disease was estimated based on the odd ratio (OR) values. The calculations were made with the use of Statistica software package, version 6, www.statsoff.com and Microsoft Office Excel-2003. Results. The statistically significant association of type 1 diabetes mellitus with T allele and AA rs689 genotype was documented for the Russian, Bashkir, Udmurtian, and Yakutian populations. The protective marker in these populations were T allele and T+ genotype. A similar association was not found for the Buryat population characterized by the lowest diabetes morbidity rate. This population was significantly different from the remaining ones in the high frequency of A allele (87% vs 69-75%; p є [0.0002-0.004]) and AA genotype (77% vs 45-60%; p є [0.00006-0.01]). Conclusion. This study has demonstrated the inter-population differences in the frequency of rs689 alleles and the population-specific differences in the association of rs689 alleles with type 1 diabetes mellitus. It is concluded that the consideration of population-related peculiarities of clinical and genetic associations is an indispensable precondition for the further development of personalized medicine.