Abstract: Objective　To analyze the genotype and clinical characteristics of Alport syndrome in children. Methods Clinical manifestation and genetic test results of 1 Chinese boy with Alport syndrome were retrospectively analyzed. Results The 11-year-old male patient presented with unexplained hematuria and proteinuria with mild renal dysfunction 4 years ago and progressed to the uremia stage of chronic kidney disease due to poor treatment compliance. There was no high-frequency hearing impairment and ocular fundus pathology. Renal biopsy showed chronic sclerosing glomerular disease and diffuse tubular atrophy (atrophy area over 80%). Immunofluorescence staining of basement membrane of alpha 3 and alpha 5 (IV) were positive. Gene sequencing identified a hemizygous mutation of c.2631dupA (insertion) in COL4A5 gene, resulted in amino acid changes of p.G878Rfs*20 (prematurely termination of protein translation after 20 amino acids). It was identified as a de novo mutation. According to ACMG guidelines. This variant is classified as pathogenic. It has not been reported in the HGMDpro database. Conclusion　Gene sequencing is helpful for the diagnosis of Alport syndrome and the discovery of novel variant of COL4A5 gene.

Key words: genetic mutation;　COL4A5;　Alport syndrome