Improved molecular diagnosis of dystrophinopathies in an unselected clinical cohort

Am J Med Genet A. 2005 Apr 30;134(3):295-8. doi: 10.1002/ajmg.a.30617.


Mutations in the DMD gene result in Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD). Readily available clinical tests detect only deletions of one exon or greater, which are found in approximately 60% of cases. Mutational analysis of other types of DMD mutations, such as premature stop codons and small frameshifting insertions or deletions, has historically been hampered by the large size of the gene. We have recently reported a method that allows the rapid and economical sequencing of the entire coding region of the DMD gene, and that is more sensitive than methods based on single-strand conformational polymorphism (SSCP) screening or other preliminary screening steps. Here we use single condition amplification/internal primer (SCAIP) sequencing analysis, in combination with multiplex amplifiable probe hybridization (MAPH) analysis of duplications, to report the frequency of mutations in a large cohort of unselected dystrophinopathy patients from a single clinic. Our results indicate that 7% of dystrophinopathy patients do not have coding region mutations, suggesting that intronic mutations are not uncommon. The availability of rapid and thorough mutation analysis from peripheral blood samples, along with an improved estimate of the percentage of non-coding region mutations, will be of benefit for improved genetic counseling and in identification of cohorts for clinical trials.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Codon, Nonsense
  • Cohort Studies
  • DNA / chemistry
  • DNA / genetics
  • DNA Mutational Analysis / methods
  • Dystrophin / genetics*
  • Exons / genetics
  • Frameshift Mutation
  • Gene Deletion
  • Gene Duplication
  • Humans
  • Muscular Dystrophy, Duchenne / diagnosis
  • Muscular Dystrophy, Duchenne / genetics*
  • Mutagenesis, Insertional
  • Mutation*
  • Mutation, Missense
  • Phenotype
  • Polymorphism, Single-Stranded Conformational


  • Codon, Nonsense
  • Dystrophin
  • DNA