Felix Claverie-Martin1, Jorge Trujillo-Suarez2, Hilaria Gonzalez-Acosta2, Cristina Aparicio3, Maria L Justa Roldan4, Blanka Stiburkova5, Kimiyoshi Ichida6, Maria A Martín-Gomez7, Maria Herrero Goñi8, Marta Carrasco Hidalgo-Barquero9, Victoria Iñigo10, Ricardo Enriquez11, Elizabeth Cordoba-Lanus2, Victor M Garcia-Nieto12. 1. Unidad de Investigación, Hospital Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain. Electronic address: fclamar@gobiernodecanarias.org. 2. Unidad de Investigación, Hospital Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain. 3. Nefrología Pediátrica, Hospital Infantil Niño Jesús, Madrid, Spain. 4. Servicio de Pediatría, Hospital Infantil Miguel Servet, Zaragoza, Spain. 5. Institute of Inherited Metabolic Disorders, Charles University, General University Hospital in Prague, Prague, Czech Republic; Institute of Rheumatology, Prague, Czech Republic. 6. Department of Pathophysiology, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan. 7. Unidad de Nefrología-Hemodialisis, Hospital de Poniente, Almeria, Spain. 8. Nefrología Pediátrica, Hospital de Cruces, Baracaldo, Spain. 9. Unidad de Nefrología Pediátrica, Hospital Materno-Infantil, Badajoz, Spain. 10. Unidad de Nefrología, Hospital Son Llàtzer, Palma de Mallorca, Spain. 11. Servicio de Nefrología, Hospital General de Elche, Spain. 12. Unidad de Nefrología Pediatrica, Hospital Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain.
Abstract
BACKGROUND: Renal hypouricemia (RHUC), a rare inherited disorder characterized by impaired uric acid (UA) reabsorption in the proximal tubule, is caused by mutations in SLC22A12 or SLC2A9. Most mutations have been identified in Japanese patients, and only a few have been detected in Europeans. METHODS: We report clinical, biochemical and genetics findings of fourteen Spanish patients, six Caucasians and eight of Roma ethnia, diagnosed with idiopathic RHUC. Two of the patients presented exercise-induced acute renal failure and another one had several episodes of nephrolithiasis and four of them had progressive deterioration of renal function, while the rest were asymptomatic. RESULTS: Molecular analysis revealed SLC22A12 mutations in ten of the patients, and SLC2A9 mutations in the other four. A new heterozygous SLC22A12 missense mutation, c.1427C>A (p.A476D), was identified in two affected members of the same family. The rest of the patients presented homozygous, heterozygous or compound heterozygous mutations that have been previously identified in patients with RHUC; SLC22A12 p.T467M and p.L415_G417del, and SLC2A9 p.T125M. Expression studies in Xenopus oocytes revealed that c.1427C>A reduced UA transport but did not alter the location of URAT1 protein on the plasma membrane. CONCLUSIONS: The biochemical and clinical features of our patients together with the genetic analysis results confirmed the diagnosis of RHUC. This is the first report describing SLC22A12 and SLC2A9 mutations in Spanish patients.
BACKGROUND:Renal hypouricemia (RHUC), a rare inherited disorder characterized by impaired uric acid (UA) reabsorption in the proximal tubule, is caused by mutations in SLC22A12 or SLC2A9. Most mutations have been identified in Japanese patients, and only a few have been detected in Europeans. METHODS: We report clinical, biochemical and genetics findings of fourteen Spanish patients, six Caucasians and eight of Roma ethnia, diagnosed with idiopathic RHUC. Two of the patients presented exercise-induced acute renal failure and another one had several episodes of nephrolithiasis and four of them had progressive deterioration of renal function, while the rest were asymptomatic. RESULTS: Molecular analysis revealed SLC22A12 mutations in ten of the patients, and SLC2A9 mutations in the other four. A new heterozygous SLC22A12 missense mutation, c.1427C>A (p.A476D), was identified in two affected members of the same family. The rest of the patients presented homozygous, heterozygous or compound heterozygous mutations that have been previously identified in patients with RHUC; SLC22A12p.T467M and p.L415_G417del, and SLC2A9p.T125M. Expression studies in Xenopus oocytes revealed that c.1427C>A reduced UA transport but did not alter the location of URAT1 protein on the plasma membrane. CONCLUSIONS: The biochemical and clinical features of our patients together with the genetic analysis results confirmed the diagnosis of RHUC. This is the first report describing SLC22A12 and SLC2A9 mutations in Spanish patients.
Authors: Jiří Vávra; Andrea Mančíková; Kateřina Pavelcová; Lenka Hasíková; Jana Bohatá; Blanka Stibůrková Journal: Cells Date: 2022-03-22 Impact factor: 6.600