Molecular basis of myotonic dystrophy: expansion of a trinucleotide (CTG) repeat at the 3' end of a transcript encoding a protein kinase family member

Cell. 1992 Feb 21;68(4):799-808. doi: 10.1016/0092-8674(92)90154-5.


Using positional cloning strategies, we have identified a CTG triplet repeat that undergoes expansion in myotonic dystrophy patients. This sequence is highly variable in the normal population. PCR analysis of the interval containing this repeat indicates that unaffected individuals have been 5 and 27 copies. Myotonic dystrophy patients who are minimally affected have at least 50 repeats, while more severely affected patients have expansion of the repeat containing segment up to several kilobase pairs. The CTG repeat is transcribed and is located in the 3' untranslated region of an mRNA that is expressed in tissues affected by myotonic dystrophy. This mRNA encodes a polypeptide that is a member of the protein kinase family.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Chromosome Mapping
  • Cloning, Molecular
  • Cyclic AMP
  • Gene Expression Regulation
  • Humans
  • Molecular Sequence Data
  • Myotonic Dystrophy / diagnosis
  • Myotonic Dystrophy / genetics*
  • Pedigree
  • Polymerase Chain Reaction
  • Protein Kinases / genetics*
  • Sequence Alignment


  • Cyclic AMP
  • Protein Kinases

Associated data

  • GENBANK/M84181
  • GENBANK/M84182
  • GENBANK/M94203
  • GENBANK/S72766
  • GENBANK/S72767
  • GENBANK/S72768
  • GENBANK/S72769
  • GENBANK/S72771
  • GENBANK/S82576
  • GENBANK/X63098