The molecular basis for Duchenne versus Becker muscular dystrophy: correlation of severity with type of deletion

Am J Hum Genet. 1989 Oct;45(4):498-506.


About 60% of both Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) is due to deletions of the dystrophin gene. For cases with a deletion mutation, the "reading frame" hypothesis predicts that BMD patients produce a semifunctional, internally deleted dystrophin protein, whereas DMD patients produce a severely truncated protein that would be unstable. To test the validity of this theory, we analyzed 258 independent deletions at the DMD/BMD locus. The correlation between phenotype and type of deletion mutation is in agreement with the "reading frame" theory in 92% of cases and is of diagnostic and prognostic significance. The distribution and frequency of deletions spanning the entire locus suggests that many "in-frame" deletions of the dystrophin gene are not detected because the individuals bearing them are either asymptomatic or exhibit non-DMD/non-BMD clinical features.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Child
  • Chromosome Deletion*
  • Cloning, Molecular
  • DNA Probes
  • Deoxyribonuclease HindIII
  • Dystrophin / genetics*
  • Exons
  • Humans
  • Muscular Dystrophies / classification
  • Muscular Dystrophies / genetics*
  • Muscular Dystrophies / physiopathology
  • Mutation*
  • Reading Frames
  • Restriction Mapping
  • Transcription, Genetic


  • DNA Probes
  • Dystrophin
  • Deoxyribonuclease HindIII