Case Report: A Novel Heterozygous Mutation of CD2AP in a Chinese Family With Proteinuria Leads to Focal Segmental Glomerulosclerosis

Yu-Xing Liu,Ai-Qian Zhang,Chen-Yu Wang,Fang-Mei Luo,Lv Liu,Yue Sheng,Liangliang Fan,Yi Dong

doi:10.3389/fped.2021.687455

Abstract

Idiopathic focal segmental glomerulosclerosis (FSGS) is a relatively frequent kidney disorder that manifest clinically as proteinuria and progressive loss of renal function. Genetic factors play a dominant role in the occurrence of FSGS. CD2-associated protein (CD2AP) is an adapter molecule and is essential for the slit-diaphragm assembly and function. Mutations in the CD2AP gene can contribute to FSGS development. Here, we describe a Chinese family of four generations with unexplained proteinuria. The proband, a 12-year-old boy, was diagnosed as FSGS. Whole-exome sequencing (WES) revealed an unknown frameshift insertion mutation (p.K579Efs*7) of CD2AP gene that leads to a truncation of CD2AP protein. Bioinformatics strategies predicted that the novel mutation was pathogenic. The mutation was absent in either healthy family members or our 200 healthy controls. In summary, we used WES to explore the genetic lesion of FSGS patients and identified a novel mutation in CD2AP gene. This work broadens the mutation spectrum of CD2AP gene and provides data for genetic counseling to additional FSGS patients.

Highlights

Idiopathic focal segmental glomerulosclerosis (FSGS) is a relatively frequent kidney disorder that manifests clinically as proteinuria and progressive deterioration of renal function
We described a Chinese family with unexplained proteinuria
Employing Whole-exome sequencing (WES) combined with bioinformatics strategies, a newly heterozygous mutation (p.K579Efs∗7) of the CD2-associated protein (CD2AP) gene was detected

Summary

INTRODUCTION

Idiopathic focal segmental glomerulosclerosis (FSGS) is a relatively frequent kidney disorder that manifests clinically as proteinuria and progressive deterioration of renal function. FSGS is histologically characterized by focal and segmental glomerular sclerosis and foot-process effacement [1]. As a leading cause of steroid-resistant nephrotic syndrome (SRNS), FSGS makes up about three quarters of the SRNS in children and adults and frequently leads to end-stage renal disease [2]. Genetic factors play a dominant role in the occurrence and development of FSGS. As a kind of podocytopathy, many FSGS-causing genes have been identified and are mainly expressed in glomerular podocytes. The proteins encoded by these genes are crucial for the maintenance of podocyte structure and function, including protein assembly of glomerular basement membrane (GBM) and podocyte skeleton [1]. At least 60 genes have been linked to

A Novel Heterozygous CD2AP Mutation in FSGS

DISCUSSION

CONCLUSION

Findings

ETHICS STATEMENT