Genetic analysis of ABCG2 and SLC2A9 gene polymorphisms in gouty arthritis in a Korean population

Abstract

Background/aims: Gout is a common inf lammatory arthritis triggered by the crystallization of uric acid in the joints. Serum uric acid levels are highly heritable, suggesting a strong genetic component. Independent studies to confirm the genetic associations with gout in various ethnic populations are warranted. We investigated the association of polymorphisms in the ABCG2 and SLC2A9 genes with gout in Korean patients and healthy individuals.

Methods: We consecutively enrolled 109 patients with gout and 102 healthy controls. The diagnosis of gout was based on the preliminary criteria of the America College of Rheumatology. Genomic DNA was extracted from whole blood samples. We identified single nucleotide polymorphism (SNP) changes in the ABCG2 and SLC2A9 genes using a direct sequencing technique. rs2231142 in ABCG2 and rs6449213 and rs16890979 in SLC2A9 and nearby regions were amplified by polymerase chain reaction.

Results: Patients with gout had significantly higher A/A genotype (29.3% vs. 4.9%, respectively) and A allele (52.8% vs. 26.5%, respectively) frequencies of rs2231142 in ABCG2 than did controls (χ(2) = 29.42, p < 0.001; odds ratio, 3.32; 95% confidence interval, 2.11 to 5.20). We found novel polymorphisms (c.881A>G and c.1002+78G>A) in the SLC2A9 gene. The univariate logistic regression analysis revealed that the c.881A>G and c.1002+78G>A SNPs were significantly higher in patients than in controls.

Conclusions: We demonstrated a significant association between rs2231142 in the ABCG2 gene and gout and identified novel SNPs, c.881A>G and c.1002+78G>A, in the SLC2A9 gene that may be associated with gout in a Korean population.

Keywords: ABCG2; Gout; SLC2A9.

Figure 1.

Among the four single nucleotide polymorphisms in the SLC2A9 gene, c.881A>G and c.1002+78G>A showed a tight linkage (|D’| = 1, r² = 0.672).