Detection of mutations in 30 exons of COL4A5 gene from X-Iinked Alport syndrome patients / 中华肾脏病杂志

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.

Correlation between X-Inactivation of Different Tissues and Phenotypes in Female with X-Linked Alport Syndrome / 实用儿科临床杂志

Objective To explore the correlation between phenotypes in female with X-linked Alport syndrome(XLAS) and X-inactivation of different tissues.Methods Thirty-six female diagnosed as XLAS were studied,and proteinuria was taken as a marker of the severity of clinical phenotypes.X-inactivation patterns were analyzed in peripheral blood cells of 36 XLAS female and in skin fibroblasts of 12 XLAS female.The X-inactivation analysis was performed by using Hpa Ⅱ predigestion of DNA followed by polymerase chain reaction(PCR) of the highly polymorphic CAG repeat of the androgen receptor gene.Results The average X-inactivation levels of the mutant allele decreased while the degree of proteinuria increased,so there was a negative correlation between the degree of proteinuria and the X-inactivation ratios of the mutant allele in blood cells(r=-0.543,P=0.002).However,there was no correlation between the degree of proteinuria and the X-inactivation ratios of the mutant allele in skin fibroblasts(r=-0.131,P=0.701).Conclusions X-inactivation ratios might explain partially the diverse phenotypes in XLAS female patients,which suggested that the prognosis of XLAS female might be predicted via analysis of the X-inactivation in peripheral blood cells.