Molecular Analysis of Duchenne muscular dystrophy / 中华实用儿科临床杂志

ABSTRACT

Objective To detect the mutation type and size variation of the dystrophy gene in Duchenne muscular dystrophy(DMD) patients,and discuss the strategy of molecular genetic diagnosis for DMD.Methods Multiplex ligation-dependent probe amplification(MLPA) and next-generation sequencing(NGS) were applied for genetic detection in patients with clinical suspected DMD.Sanger sequencing was performed to confirm the results.Results Pathogenic mutations were found in 28 cases with DMD.Twenty-two of the 28 cases were found to be positive with MLPA analysis,16 cases with deletion mutations,4 cases with duplication,and 2 cases with both deletion and duplication mutations.Then,NGS technology was performed to detect 5 cases with MLPA positive and 1 case with MLPA negative,which were chosen optionally,and 3 cases showed deletion (exon51 del,chrX31779857-31795289; exon53 del,chrX31685440-31747548; exon51-55 del,chrX31632504-31827732) and 2 cases of duplication (exon45 dup,chrX31970766-32023816 ; exon55 dup,chrX31540860-31649750),which were consistent with MLPA analysis.Meanwhile,NGS could determine the location of break point and the size of DNA segments accurately and also detect one point mutation which was MLPA negative.In the end,Sanger sequencing was performed to confirm this point mutation.Conclusions The mutational spectrum of the DMD gene is complex,including deletion/duplication and point mutations,and MLPA is an efficient method for detecting paternal deletion and duplication of DMD,while NGS can not only detect both deletion/duplication and point mutations,but also determine the location of break point and the size of gene segments accurately.Next-generation sequencing may be a powerful technology for early clinical diagnosis,prognostic judgment and prenatal diagnosis of DMD.