Novel deletion mutation in a Chinese family with X-linked alport syndrome

Backgrounds and Objectives: alport syndrome (AS) is a progressive hereditary condition that is characterized by haematuria, proteinuria, progressive renal impairment, and end stage kidney disease (ESRD). Approximately 85% of AS patients have X-linked mutations in the COL4A5 gene that encodes type IV collagen. The aim of our study was to identify the gene responsible for glomerulopathy in a 3-generation Chinese pedigree with familial haematuria. Methods: We examined five members of a Chinese family clinically suspected of X-linked AS caused by COL4A5 gene mutations. All 51 exons of the COL4A5 gene were screened by direct DNA sequencing. Results: We identified the novel deletion mutation c. 3990_4016delCCC...TCC in COL4A5 in three affected individuals with haematuria, but the mutation was absent in the other 2 healthy family members and 100 unrelated healthy controls. Conclusions: Our result demonstrates that the mutation is pathogenic and novel and has meaningful implications for the diagnosis and genetic counselling of cases with AS. The results in the study broaden the genotypic spectrum of known mutations for AS.