J 2019

Clinical and Functional Characterization of a Novel URAT1 Dysfunctional Variant in a Pediatric Patient with Renal Hypouricemia

STIBURKOVA, Blanka, Jana BOHATA, Iveta MINARIKOVA, Andrea MANCIKOVA, Jiri VAVRA et. al.

Basic information

Original name

Clinical and Functional Characterization of a Novel URAT1 Dysfunctional Variant in a Pediatric Patient with Renal Hypouricemia

Authors

STIBURKOVA, Blanka (203 Czech Republic, guarantor), Jana BOHATA (203 Czech Republic), Iveta MINARIKOVA (203 Czech Republic), Andrea MANCIKOVA (203 Czech Republic), Jiri VAVRA (203 Czech Republic), Vladimir KRYLOV (203 Czech Republic) and Zdeněk DOLEŽEL (203 Czech Republic, belonging to the institution)

Edition

Applied Sciences-Basel, BASEL, MDPI, 2019, 2076-3417

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

30217 Urology and nephrology

Country of publisher

Switzerland

Confidentiality degree

není předmětem státního či obchodního tajemství

References:

Impact factor

Impact factor: 2.474

RIV identification code

RIV/00216224:14110/19:00110982

Organization unit

Faculty of Medicine

UT WoS

000488603600041

Keywords in English

SLC22A12; URAT1; hypouricemia; uric acid transporters; excretion fraction of uric acid

Tags

Tags

International impact, Reviewed
Změněno: 17/2/2020 10:52, Mgr. Tereza Miškechová

Abstract

V originále

Renal hypouricemia (RHUC) is caused by an inherited defect in the main (reabsorptive) renal urate transporters, URAT1 and GLUT9. RHUC is characterized by decreased concentrations of serum uric acid and an increase in its excretion fraction. Patients suffer from hypouricemia, hyperuricosuria, urolithiasis, and even acute kidney injury. We report the clinical, biochemical, and genetic findings of a pediatric patient with hypouricemia. Sequencing analysis of the coding region of SLC22A12 and SLC2A9 and a functional study of a novel RHUC1 variant in the Xenopus expression system were performed. The proband showed persistent hypouricemia (67-70 mu mol/L; ref. range 120-360 mu mol/L) and hyperuricosuria (24-34%; ref. range 7.3 +/- 1.3%). The sequencing analysis identified common non-synonymous allelic variants c.73G > A, c.844G > A, c.1049C > T in the SLC2A9 gene and rare variants c.973C > T, c.1300C > T in the SLC22A12 gene. Functional characterization of the novel RHUC associated c.973C > T (p. R325W) variant showed significantly decreased urate uptake, an irregular URAT1 signal on the plasma membrane, and reduced cytoplasmic staining. RHUC is an underdiagnosed disorder and unexplained hypouricemia warrants detailed metabolic and genetic investigations. A greater awareness of URAT1 and GLUT9 deficiency by primary care physicians, nephrologists, and urologists is crucial for identifying the disorder.