Genetic and epigenetic contribution of ABCG2 to gout susceptibility: a case-control study

Gout is a disease characterized by joint pain due to an inflammatory response triggered by the precipitation of monosodium urate (MSU) crystals in joints. ATP-binding cassette subfamily G member 2 (ABCG2) is a protein involved in urate transport and in the protection of cells against drugs.

Analyze the effect of the presence of the ABCG2 single nucleotide polymorphisms (SNPs) rs2231142 and rs72552713 through the analysis of ABCG2 promoter methylation and gene expression to assess their effect on the development of gout.

This is a case‒control study that included 560 subjects of Mexican origin. ABCG2 SNPs were analyzed from the DNA of peripheral blood. Expression and methylation analyses of ABCG2 were performed via RT‒qPCR.

After adjustment by age, sex, age, Body mass index (BMI), serum uric acid (SUA), glucose, and Triglycerides (TG), significant differences were observed in the distribution of the rs2231142 genotype. In the codominant model, the homozygous TT genotype was associated with an increased risk of gout (OR = 34.99, 95% CI = 13.38-91.52; P < 0.0001). A negative correlation was found between the methylation percentage and gene expression in patients (r: -0.48, P < 0.01) and the percentage of promoter methylation of ABCG2 gene was greater (p < 0.05) in individuals with the GT genotype than in those with the GG genotype among the total participants.

Changes in the expression and methylation of the ABCG2 gene in patients with gout may be associated with the presence of SNPs such as rs2231142, which appears to have functional relevance in gout susceptibility in the Mexican population studied.