Torres RJ, et al. - Authors evaluated if GLUT9, ABCG2 and URAT1 gene single nucleotide polymorphisms (SNPs) are able to influence uric acid levels and allopurinol response in patients with hypoxanthine-guanine phosphoribosyltransferase (HPRT) deficiency. Findings suggested that in patients with uric acid overproduction due to HPRT deficiency the renal handling of uric acid is influenced and serum urate levels and the response to treatment is modulated by GLUT9 SNPs.