SLC2A9 and nephrolithiasis: In addition, individuals with homozygous mutations in GLUT9 present with pronounced hypouricemia and hyperuricosuria with FEUA's of 100% or greater (indicative of net active urate secretion), response to fructose load, and a propensity for nephrolithiasis and exercise induced renal failure (62, 84, 100–102).