Objective: To study the associations of gout, tophi, and uric acid levels with the gout-related SLC2A9 (solute carrier family 2, member 9) single-nucleotide polymorphisms (SNPs) between two different racial groups.
Methods: We genotyped eight SLC2A9 SNPs in 109 gout and 191 control subjects from male Han Chinese in Taiwan, and 69 gout and 168 control subjects from Solomon Islands.
Results: Nonsynonymous SLC2A9 rs3733591 Arg265His was associated with risk for gout and tophaceous gout in Han Chinese (p=0.0012 and p=0.0044). Genetic effect of this SNP on tophaceous gout was replicated in Solomon Islanders (p=0.0184). Patients with SLC2A9 Arg265His risk C-allele consistently had higher risk for tophi (OR=2.05-2.15) than non-tophi (OR=0.91-1.62). SNP rs3733591 described 3.68% and 5.98% of the total variability in uric acid levels for Chinese and Solomon Islands peoples, respectively.
Conclusion: Nonsynonymous SNP rs3733591 variant within SLC2A9 gene from two geographically diverse populations served as an important genetic checkpoint for tophaceous gout and increased uric acid levels.