Abstract: Objective　To investigate the clinical characteristics and related pathogenic genes of Alport syndrome. Methods　The clinical data of an Alport syndrome family were retrospectively analysed. Results　A TTCT insertion mutation (c.41_42 dup TCTT) lead to reading frame disturbance was identified in the COL4A5 gene of the proband, an 11 years and 8 months old male. Integrative Genomics Viewer software found that the frameshift mutation lead to the preterm stop codon at 40th amino acid residue and termination of protein translation. The proband's mother (II5) and grandmother (I2) both carried the mutant gene and had end-stage renal disease at the age of 35 and 34, respectively. Both of them had hearing impairment with no ocular abnormalities, which showed a co-segregation association with the affected members of the families. Conclusions　This study provides evidence of molecular genetics for the clinical diagnosis of this family and expands the mutation spectrum of COL4A5 gene.

Key words: X-linked alport syndrome;　Insertion mutation;　whole-exome sequencing;　next generation sequencing