Multiple single nucleotide polymorphisms in the human urate transporter 1 (hURAT1) gene are associated with hyperuricaemia in Han Chinese

Abstract

Objective: The present study investigated whether single nucleotide polymorphisms (SNPs) in the human urate transporter 1 (hURAT1) gene are associated with primary hyperuricaemia (HUA) in Han Chinese people. Methods: A total of 538 subjects (215 cases and 323 control subjects) were recruited from Qingdao, China. SNPs in potentially functional regions of the gene were identified and genotypes determined by direct sequencing. Association analyses were conducted using Fisher's exact test and logistic regression assuming a genotype model. Results: By sequencing the promoter, 10 exons, and the exon-intron junctions of the hURAT1 gene, 14 SNPs were identified. Two of the SNPs identified were associated with susceptibility to HUA. The first was a rare intron 3 (11 G→A) SNP (p=0.0005), where carriers of the 'A' allele had a 3.4-fold (95% CI 1.67 to 6.93) increased risk of HUA. The second was a common exon 8 (T1309C) SNP (rs7932775), where carriers of one and two 'C' alleles had respective fold increased risks of 1.64 (95% CI 1.07 to 2.52) and 2.32 (95% CI 1.37 to 3.95). These SNPs had a joint additive effect of risk of HUA, with those individuals carrying at least one 'A' allele at the intron 3 SNP and two 'C' alleles at rs7932775 having a 5.88-fold (95% CI 1.25 to 15.57) increased risk of HUA in comparison to those with no risk alleles. Conclusion: In conjunction with other studies, our results suggest that there are multiple genetic variants within or near hURAT1 that are associated with susceptibility to HUA in Han Chinese, including a novel SNP located in intron 3.