# Renal insufficiency caused by TMEM216 gene mutation: Case Report

## TL;DR

A 21-year-old man with chronic kidney disease was found to have TMEM216 gene mutations, linking this genetic variant to severe renal failure and expanding its known clinical effects.

## Contribution

This case expands the clinical phenotypic spectrum of TMEM216 mutations and highlights their role in CKD progression.

## Key findings

- Compound heterozygous TMEM216 mutations were identified in a patient with progressive renal failure.
- TMEM216 mutations may disrupt renal tubular epithelial cell function, leading to proteinuria and CKD.
- Genetic testing is suggested as an early diagnostic tool for young patients with unexplained CKD.

## Abstract

Chronic kidney disease (CKD) is a globally prevalent condition characterized by high morbidity and a progressive course that often culminates in end-stage renal disease (ESRD), necessitating dialysis or kidney transplantation. In recent years, genetic factors have received increasing attention in the pathogenesis of CKD, particularly among patients with unexplained renal dysfunction. Genetic screening has emerged as a valuable diagnostic tool. Mutations in the TMEM216 gene, a pathogenic variant associated with ciliopathy, have been implicated in severe renal impairment. This study presents a case analysis that explores the impact of TMEM216 mutations on kidney function and their potential clinical significance.

We report a case of a 21-year-old male who developed proteinuria at the age of 15 without an apparent cause. Over the subsequent 6 years, his serum creatinine levels gradually increased, ultimately progressing to ESRD, accompanied by complications such as hypertension and secondary hyperparathyroidism. Imaging studies revealed bilateral renal cysts and a congenital bicuspid aortic valve. Whole-exome sequencing identified compound heterozygous mutations in TMEM216 [c.253C > T (p.R85*) and c.143 T > C (p.L48P)], consistent with an autosomal recessive inheritance pattern. Family analysis indicated that each parent carried one of the mutations. The combination of clinical and genetic findings suggests that the patient’s renal insufficiency may be attributed to TMEM216 mutations, highlighting their potential role in the progression of CKD.

This study presents a severe case of renal dysfunction attributed to mutations in the TMEM216 gene, thereby expanding the clinical phenotypic spectrum associated with this gene. Mutations in ciliopathy-related genes may contribute to proteinuria and renal failure by disrupting the polarization and functionality of renal tubular epithelial cells. For young patients with unexplained CKD, genetic testing can serve as an early diagnostic tool to identify the underlying etiology and facilitate personalized treatment strategies. Future research on TMEM216-related nephropathy should aim to further elucidate its pathogenic mechanisms and explore potential therapeutic targets to enhance patient outcomes and advance precision medicine.