Open Access Case report

Recurrent exercise-induced acute kidney injury by idiopathic renal hypouricemia with a novel mutation in the SLC2A9 gene and literature review

Huijun Shen1, Chunyue Feng1, Xia Jin1, Jianhua Mao1*, Haidong Fu1, Weizhong Gu2, Ai’min Liu1, Qiang Shu1 and Lizhong Du1

Author Affiliations

1 Department of Nephrology, The Children’s Hospital of Zhejiang University School of Medicine, Hangzhou 310003, Zhejiang Province, China

2 Department of Pathology, The Children’s Hospital of Zhejiang University School of Medicine, Hangzhou 310003, China

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BMC Pediatrics 2014, 14:73  doi:10.1186/1471-2431-14-73

Published: 14 March 2014

Abstract

Background

Idiopathic renal hypouricemia (iRHUC) is an autosomal recessive hereditary disorder, characterized by impaired tubular uric acid transport, re-absorption insufficiency and/or the acceleration of secretions. Some patients present with severe complications, such as exercise-induced acute kidney injury (EIAKI) and nephrolithiasis.

Case presentation

Herein, we report the case of a girl with severe iRHUC (serum urate 0.05 mg/dL, fractional excretion of uric acid 295.99%) associated with recurrent EIAKI, in whom the disease was caused by a homozygous mutation (g.68G > A in exon 3) in the SLC2A9 gene. Her family members (father, mother and brother) carried the same mutation but were heterozygous, without any signs of severe hypouricemia.

Conclusions

Our findings indicate that iRHUC is a rare disorder but that it should also be considered in patients with EIAKI, especially in those patients who manifest with moderately elevated or normal serum concentrations of uric acid during the acute phase of AKI. Mutational screening of the SLC2A9 gene is necessary for the diagnosis of iRHUC, and homozygous mutations of the SLC2A9 alleles can cause severe hypouricemia. Careful attention should be paid to any signs of hypouricemia during the recovery phase of AKI and long-term follow-up.

Keywords:
Idiopathic renal hypouricemia; Acute kidney injury; SLC2A9; Gene mutation