One study of 17 patients with renal hypouricemia and exercise-induced acute kidney injury (EI-AKI), for whom both the URAT1 and GLUT9 genes were sequenced, showed that 13 were homozygous or compound heterozygous for mutant URAT1 alleles, two were heterozygous for mutant URAT1 alleles, and only one was compound heterozygous for mutant GLUT9 alleles (both of the two mutant GLUT9 alleles differed from those reported by Matsuo et al. [7] or Anzai et al. [22,23]). This evidence concerns the gene SLC22A12 and hypouricemia, renal.