A study of possible heterogeneity in Duchenne muscular dystrophy

Clin Genet. 1979 May;15(5):444-9. doi: 10.1111/j.1399-0004.1979.tb01777.x.


One possible explanation for the apparently high birth incidence of Duchenne muscular dystrophy (DMD), a lethal X-linked disorder, is genetic heterogeneity. As a first step in possibly demonstrating genetic heterogeneity, affected boys were sub-divided into those with and without severe mental handicap. In those with severe mental handicap, ages at onset and of becoming confined to a wheelchair were later, the fall in SCK level with age was less marked, and the urinary excretion of certain aminoacids was greater than in affected boys with normal intelligence. Though the number of subjects investigated was relatively small (15 in each group) and further studies are therefore needed, the results suggest that DMD may not be a single disease entity.

MeSH terms

  • Adolescent
  • Age Factors
  • Amino Acids / urine
  • Arrhythmias, Cardiac / etiology
  • Child
  • Child, Preschool
  • Creatine Kinase / blood
  • Female
  • Humans
  • Intellectual Disability / genetics
  • Male
  • Muscular Dystrophies / enzymology
  • Muscular Dystrophies / genetics*
  • Muscular Dystrophies / urine
  • X Chromosome


  • Amino Acids
  • Creatine Kinase