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Abstract: FR-PO609

Juvenile Nephronophthisis Caused by Two New XPNPEP3 Gene Mutations: A Case Report

Session Information

Category: Genetic Diseases of the Kidneys

  • 1202 Genetic Diseases of the Kidneys: Non-Cystic

Authors

  • Tang, Xunzi, Department of Nephrology, The Second Xiangya Hospital, Central South University, Hunan Key Laboratory of Kidney Disease and Blood Purification, Changsha, China
  • Xia, Ming, Department of Nephrology, The Second Xiangya Hospital, Central South University, Hunan Key Laboratory of Kidney Disease and Blood Purification, Changsha, China
  • Fan, Xinyan, Department of Nephrology, The Second Xiangya Hospital, Central South University, Hunan Key Laboratory of Kidney Disease and Blood Purification, Changsha, China
  • Zhao, Juanyong, Department of Nephrology, The Second Xiangya Hospital, Central South University, Hunan Key Laboratory of Kidney Disease and Blood Purification, Changsha, China
  • Liu, Hong, Department of Nephrology, The Second Xiangya Hospital, Central South University, Hunan Key Laboratory of Kidney Disease and Blood Purification, Changsha, China
Introduction

Nephronophthisis(NPHP) is an autosomal recessive disease that mainly involves the tubulointerstitium. This article reports a case of a juvenile type of Nephronophthisis with a small proportion of urine, an increase in serum creatinine and anemia of uric acid, as the main clinical manifestations, renal pathological features of renal tubule atrophy, renal tubule membrane thickening, fibrosis, and inflammatory cell infiltration. The whole exome of the XPNPEP3 gene showed two mutations: CHR22:41278058,c.466(exon 3) C>T, and Chr22:41253249,c.64(exon 1) G>A, which caused Nephronophthisis. These two mutations are novel mutations of the XPNPEP3 genes.

Case Description

The patient, a 14-year-old male, was admitted to the hospital because of "abnormal renal function for 3 years." Pathological diagnosis: Proliferative sclerosing glomerulonephritis with chronic renal tubulointerstitial nephropathy is initially considered, and genetic screening is recommended. The whole exome of the XPNPEP3 gene showed two mutations: CHR22:41278058,c. 466(exon 3) C>T, and Chr22:41253249,c. 64(exon 1) G>A. Mutations in this gene can lead to Nephronophthisis. The clinical diagnosis was: 1. Nephronophthisis 2. Chronic renal insufficiency 3. Metabolic syndrome, Category 1 high blood pressure, high-risk glucose tolerance, abnormal abdominal obesity 4. Hyperuricemia 5. mild anemia. At present, the patient is still under regular follow-up.

Discussion

Nephronophthisis(NPHP) is an autosomal recessive disease that primarily involves the renal tubulointerstitium. NPHP is characterized by normal or reduced renal size, renal cysts concentrated at the corticomedullary junction, and tubulointerstitial fibrosis. Whole exome sequencing of the XPNPEP3 gene showed two NPHP-causing variants, Whole exome sequencing of the patient's father and mother confirmed the existence of compound heterozygous mutations. The clinical manifestations of the patient were partially consistent with Nephronophthisis type 1. At present, there is no specific drug for the treatment of Nephronophthisis, and the principle of clinical treatment is supportive therapy. Risk factors leading to renal injury and complications should be controlled. Hormones should be avoided in patients with hypertension, worsening renal function, edema, or hyperkalemia.