Ján Radvánszky1, Peter Špalek2, Ľudevít Kádaši1,3
Myotonic dystrophy (DM) is genetically determined progressive and degenerative disorder of skeletal muscles. Besides involvement of skeletal muscles, DM may cause eye, heart, endocrine and brain disorders. DM comprises at least two genetically distinct forms. DM1 is caused by an expansion of a CTG repeat in the DMPK gene, while expansion of a CCTG repeat in the ZNF9 (CNBP) gene causes DM2. Strikingly similar phenotypic presentations of both types may be a consequence of common pathogenic mechanisms likely connected to the expansion containing RNA transcripts. On the other hand, the differences between DM1 and DM2 may be a consequence of specific interactions of the CUG and CCUG transcripts, and of locus specific effects of these expansions. Together with the extending knowledge about the pathogenic processes leading to DM, there are also a grooving number of clinical studies aimed to find possible therapeutic approaches. Therefore, molecular methods suitable for the direct identification of the expansions and the establishment of national and international patient registries will play crucial role in the healthcare of the patients with DM in the near future.