RESUMO
Objective To screen the mutations in 30 exons of COL4A5 gene from X-linked Alport syndrome. Methods 20 Chinese X-linked Alport syndrome patients from 16 families were examined. Genomic DNA was extracted from peripheral leukocyte and exon-specific primers were designed for 30 exons(1-25、31、 32、41、 50、51) . Polymerase chain reaction amplification was performed and followed bydegenerating gel gradient electrophoresis (DGGE) analysis. All abnormal migration bands were sequenced and one hundred normal persons selected as control. Results Four abnormal bands were detected, which were all point mutations and predicted to be functionally pathogenic, in four unrelated patients. One patienthad a nonsense mutation in exon 1 (Glu 22 Term); one had a missense mutation in exon 3l(Gly852Val).Two patients carried splicing mutations in intron 1 and 25 respectively(283+1G→T、2150 + 1G→T) .Conclusions X-linked Alport syndrome is caused by various kinds of COL4A5 gene mutations without any hotspot. Paralleled with the significance of exon mutations, intron mutations also play a critical role in the pathogenesis. Furthermore, these four pathogenic mutations have never been reported in the genebank and showed good correlation with clinical manifestations.