TRPC6 Mutational Analysis in Iranian Children With Focal Segmental Glomerulosclerosis.

INTRODUCTION: Focal segmental glomerulosclerosis (FSGS) ranks among nephrotic syndromes. Research shows that FSGS is brought about by several genes including transient receptor potential cation channel subfamily c member 6 (TRPC6). This study aimed to investigate TRPC6 gene in Iranian FSGS children.

MATERIALS AND METHODS: Twenty-six FSGS patients were included. They were all under 16 years old. Polymerase chain reaction amplification and sequencing were performed to examine exons 2 and 13 of TRPC6 gene.

RESULTS: Sampling was performed when the patients had a mean age of 9.26 ± 3.19 years. Sixteen children were boys (61.5%); male-female ratio was 1.35:1. Four patients (15.4%) were diagnosed with TRPC6 variants. Three missense nonsynonymous mutations (C121S, D130V, and G162R) and 1 synonymous mutation (I111I) were detected. All variants were novel; in silico analysis predicted D130V and G162R as pathogenic. Patients with and without mutations were not different significantly regarding age at disease onset, sex, consanguinity, hypertension, hematuria, serum creatinine and albumin, rate of progression to kidney failure, response to steroids, and resistance to cyclosporine A and cyclophosphamide.

CONCLUSIONS: This study examined exons 2 and 13 of TRPC6 gene in Iranian FSGS children. Four novel TRPC6 variants were detected; in silico analysis showed that 2 variants (D130V and G162R) could be pathogenic. It could be concluded that TRPC6 may be useful for genetic screening in Iranian FSGS children.