Analysis of polymorphisms in the promoter region of interleukin-1beta by restriction fragment length polymorphism-PCR.

Objective: To investigate the frequencies of -1470, -511 and -31 single nucleotide polymorphisms (SNPs) in the promoter of IL-1beta and its haplotype constitution in Chongqing population.

Methods: One hundred and twelve healthy Chongqing people were enrolled in this study. Polymorphisms at -1470 (G to C), -511 (T to C) and -31 (C to T) of IL-1beta were genotyped with the method of restriction fragment length polymorphism (RFLP). Haplotype frequencies were analyzed by Arlequine software.

Results: Frequencies of IL-1beta -1470, -511 and -31 SNPs were 41.67%, 50% and 45.33%, respectively. Genotype frequencies of -1470 locus were 39.81%, 37.04% and 23.15% for G/G, G/C and C/C respectively. As for T-511C SNP, genotype frequencies of T/T, T/C and C/C were 29.91%, 40.18% and 29.91%, respectively. Genotyping results of C/C, C/T, and T/T of -31 locus were 35.51%, 38.32% and 26.71% respectively. Haplotype analysis found that there were mainly three haplotypes constituted by three SNPs, ie., G-T-C, C-T-C and G-C-T.

Conclusions: Polymorphisms exist in the promoter of IL-1beta in Chongqing population. Three SNPs locate in the same haplotype block.