Journal of Neurology

, Volume 251, Issue 10, pp 1173–1182

Myotonic dystrophy type 2 and related myotonic disorders


DOI: 10.1007/s00415-004-0590-1

Cite this article as:
Meola, G. & Moxley, R.T. J Neurol (2004) 251: 1173. doi:10.1007/s00415-004-0590-1


The myotonic dystrophies are a group of dominantly inherited disorders characterized by muscle wasting, myotonia, cataracts, hypogonadism and other system manifestations. Myotonic dystrophy type 1 (DM1) results from an unstable expansion of a CTG repeat in 3’ UTR of the DM protein kinase (DMPK) gene on chromosome 19q 13.3. Myotonic dystrophy type 2 (DM2) is caused by an unstable expansion of a CCTG tetraplet repeat in intron 1 of the zinc finger 9 (ZFN9 gene) on chromosome 3q 21.3. However, the clinical diagnosis of DM2 is more complex than that of DM1, and conventional molecular genetic methods used for diagnosis of DM1 are not helpful for DM2. We here describe the detailed clinical, laboratory and biomolecular tests to identify DM2 and related myotonic disorders. At present, foci of accumulated noncoding CCTG repeat RNA (ribonuclear inclusions) in the cell nuclei are thought to interfere with the regulation and expression of several genes at the basis of multisystemic aspects of myotonic dystrophy type 2.

Key words

myotonic dystrophy type 2myotonic dystrophy type 1DM1DM2DMPKZFN9

Copyright information

© Steinkopff Verlag 2004

Authors and Affiliations

  1. 1.Department of NeurologyUniversity of Milan, Istituto Policlinico San DonatoSan Donato Milanese, MilanItaly
  2. 2.Department of NeurologyUniversity of Rochester, Strong Memorial HospitalRochesterUSA