Novel deletion mutation of type-Ⅳcollagen in a Chinese family with Alport syndrome / 医学研究生学报

ABSTRACT

Objective Alport syndrome is one of the diseases that may lead to the end-stage renal disease ( ESRD) in chil-dren, and the methods for its diagnosis and treatment remain quite limited.This study aimed to investigate the clinical and genetic di-agnosis of a Chinese family with hematuria companied by genetic nephritis. Methods We analyzed the renal pathology of 7 patients in a family, performed immunofluorescence staining of type-Ⅳcollagen in the nephridial and skin tissue, conducted gene sequencing i-dentification using the exon sequence method, and examined the blood and urine samples from the patients. Results Renal patholo-gy manifested mesenterium hyperplasia in the index patient, with IgM+under the light microscope, no thickening or thinning under the electromicroscope, and no absence of type-Ⅳcollagen on immunofluorescence analysis.Mutation of c.1365_1373del TCCAGGCCC (p.Pro456_Pro458del3) was observed in exon 21 of the COL4A5 gene.Only 1682 amino acids were found in the mutated protein as compared with 1685 in the wild type. Conclusion This is the first case of Alport syndrome induced by gene deletion mutation ever reported in China and abroad.There are many female patients in this family, all with a high risk of reproduction failure.Antepartal gene diagnosis or genetic diagnosis before embryo transfer may contribute to the prevention of the disease.