Chinese and Solomon Islanders

Gout is characterised by monosodium urate crystals in hyperuricaemic individuals.1 2 Impaired excretion of urate exacerbates this condition.1 Urate transporter 1 (encoded by SLC22A12) is an urate–anion exchanger in the kidneys medi-ating urate transportation across the apical membrane of the proximal tubules.3 4 SLC22A12 has been reported to infl uence urate homeostasis in Caucasian and Japanese populations5–8 but single nucleotide polymorphism (SNP) genotype effects on gout are unclear. We studied four SLC22A12 SNP associations with gout and urate levels in male Han Chinese from Taiwan and Solomon Islanders. Clinical rheumatologists confi rmed gout/tophi cases using American College of Rheumatology (ACR) criteria.9 Our con-trols had no diagnosis of gout and were not medicated with hypouricaemic agents during outpatient visits. We enrolled 115 male patients who were gouty (40 tophi) and 202 controls (age, mean±SD 54.1±14.8 and 55.5±16.3 years, respectively) from Kaohsiung Chang-Gung Hospital and community clin-ics in Taiwan.10 We further enrolled 54 male gouty cases (age 49.4±11.2) (22 tophi) and 138 controls (age 46.0±14.0) from the National Referral Hospital of Honiara and 2 provincial mini-hospitals of Southeastern Guadalcanal in the Solomon Islands. The institutional review boards at each participating hospital approved this study. Written informed consent was obtained from all participants. We investigated two hyperuricaemia-related SNPs within SLC22A12 (rs3825016 and rs11231825)6 and two SLC22A12 tag SNPs (rs475688 and rs7932775) that were obtained from a HapMap-CHB Chinese populatio