The myotonic dystrophy gene

Arch Neurol. 1993 Nov;50(11):1173-9. doi: 10.1001/archneur.1993.00540110053005.


The myotonic dystrophy gene codes for a protein kinase and contains a repeated trinucleotide motif (adenine-guanine-cytosine [AGC]) in its transcribed sequence. The repeat is polymorphic in the general population, varying in size from five to 37 AGC units in normal alleles. Myotonic dystrophy patients show expansions of the repeated sequence from over 50 elements up to several thousand units. There is a positive correlation between repeat size and clinical severity. The direct analysis of the AGC repeat size allows an easy confirmation of the clinical diagnosis of myotonic dystrophy in difficult cases and for prenatal counseling.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Amino Acid Sequence
  • Humans
  • Molecular Sequence Data
  • Mutation
  • Myotonic Dystrophy / genetics*
  • Myotonin-Protein Kinase
  • Protein Kinases / genetics
  • Protein-Serine-Threonine Kinases*
  • Repetitive Sequences, Nucleic Acid / genetics*


  • DMPK protein, human
  • Protein Kinases
  • Myotonin-Protein Kinase
  • Protein-Serine-Threonine Kinases