Since the discovery of the human urate transporter 1 (hURAT1) gene, the number of patients diagnosed with renal hypouricaemia caused by hURAT1 gene mutation(s) has increased.
The W258X and/or R90H mutations in the SLC22A12 gene are one of the major factors responsible for hypouricaemia, and one-third of the hypouricaemic subjects had one or both of the mutant alleles.
Individuals with primary hypouricemia were differentiated from healthy individuals in the orthogonal signal correction/partial least-squares-discriminant analysis models of the NMR data with a statistically significant separation.
With the large health-examination database of the Japan Maritime Self-Defense Force, we found two missense mutations (R198C and R380W) of GLUT9/SLC2A9 in hypouricemia patients.
Our findings indicate that even a nonsense mutation responsible for the heterozygous status of SLC2A9 did not cause severe hypouricemia, and they lend support to previous speculation that mutations of both SLC2A9 alleles cause severe hypouricemia.
The episodes of EIARF were complicated by posterior reversible encephalopathy syndrome (PRES), which suggested a relationship between PRES and GLUT9 or severe hypouricemia.
The net balance between renal urate absorption and secretion is a major determinant of serum uric acid concentration and loss-of-function mutations in SLC2A9 and SLC22A12 cause hereditary hypouricaemia due to reduced urate absorption and unopposed urate secretion.
Xanthinuria due to xanthine dehydrogenase (XDH) deficiency is a rare genetic disorder characterized by hypouricemia and the accumulation of xanthine in the urine.
Mutational screening of the SLC2A9 gene is necessary for the diagnosis of iRHUC, and homozygous mutations of the SLC2A9 alleles can cause severe hypouricemia.