Exome sequencing revealed a novel splice donor mutation in disease gene of Duchenne muscular dystrop

• 作 者: 林炎鸿 邱丽萍 郑德柱 严爱贞 曾健 兰风华
• 机 构: 南京军区福州总医院临床遗传与实验医学科,福州,350025
• 出 处: 第十二次全国医学遗传学学术会议
• 发表日期: 2013年4期
• 关键词: Duchenne muscular dystrophy exome sequencing splice donor mutation bioinformatic

　　Backgroud Duchenne muscular dystrophy is the most common and lethal X-linked neuromuscular diseases, which is characterized by progressive muscle weakness and the pseudo hypertrophy of gastrocnemius.DMD typically caused by disrupting the reading frame in the dystrophin gene, approximately 75% of mutational events are represented by deletions or duplications of one or more exons in the dystrophin gene, and the remaining cases by subtle mutations, including point mutations, small indels, small inversion, and complex small rearrangements.In most cases, subtle mutations has been described that should cause premature termination codon.Methods The proband was a 9-year-old boy with typical clinical manifestations of DMD, but without exon deletions or duplications in the dystrophin gene using MLPA.For the typical clinical manifestations of the boy, exome sequencing was used in mutation detection of the patient.Then the mutation was confirmed by Sanger sequencing.And in order to know the pathogenic mechanism of the mutation, hybrid minigene splicing assay (HMSA) was used to find the effect of the mutation on the alternative splicing of dystrophin gene at the cell level.Results By the exome sequencing a base change in the first base of intron 50(G>C) of DMD gene was found, and his mother was heterozygosis at the same site.Bioinformatics predicted that the 5 donor splicing site of intron 50 disappeared, because of the base change which would alter the C terminal of corresponding peptide, result in the premature termination codon.And the result of the HMSA coincided with the prediction.Conclusions This study demonstrated that exome sequencing combined with HMSA could detect subtle mutations in the dystrophin gene effectively, which added to the system for molecular diagnosis of DMD.