New methods for molecular diagnosis and demonstration of the (CCTG)n mutation in myotonic dystrophy type 2 (DM2)

R. Sallinen, A. Vihola, L. L. Bachinski, K. Huoponen, H. Haapasalo, P. Hackman, S. Zhang, M. Sirito, H. Kalimo, G. Meola, N. Horelli-Kuitunen, M. Wessman, R. Krahe, B. Udd

Research output: Contribution to journalArticle


Myotonic dystrophy types 1 and 2 are autosomal dominant, multisystemic disorders with many similarities in their clinical manifestations. Myotonic dystrophy type 1 is caused by a (CTG)n expansion in the 3′ untranslated region of the DMPK gene in 19q13.3 and myotonic dystrophy type 2 by a (CCTG)n expansion in intron 1 of ZNF9 in 3q21.3. However, the clinical diagnosis of myotonic dystrophy type 2 is more complex than that of myotonic dystrophy type 1, and conventional molecular genetic methods used for diagnosing myotonic dystrophy type 1 are insufficient for myotonic dystrophy type 2. Herein we describe two in situ hybridization protocols for the myotonic dystrophy type 2 mutation detection. Chromogenic in situ hybridization was used to detect both the genomic expansion and the mutant transcripts in muscle biopsy sections. Chromogenic in situ hybridization can be used in routine myotonic dystrophy type 2 diagnostics. Fluorescence in situ hybridization on extended DNA fibers was used to directly visualize the myotonic dystrophy type 2 mutation and to estimate the repeat expansion sizes.

Original languageEnglish
Pages (from-to)274-283
Number of pages10
JournalNeuromuscular Disorders
Issue number4
Publication statusPublished - Apr 2004



  • In situ hybridization
  • Molecular genetic diagnosis
  • Myotonic dystrophy
  • Myotonic dystrophy type 2
  • Proximal myotonic myopathy
  • Repeat expansion disorder

ASJC Scopus subject areas

  • Clinical Neurology
  • Pediatrics, Perinatology, and Child Health
  • Developmental Neuroscience
  • Neurology

Cite this

Sallinen, R., Vihola, A., Bachinski, L. L., Huoponen, K., Haapasalo, H., Hackman, P., Zhang, S., Sirito, M., Kalimo, H., Meola, G., Horelli-Kuitunen, N., Wessman, M., Krahe, R., & Udd, B. (2004). New methods for molecular diagnosis and demonstration of the (CCTG)n mutation in myotonic dystrophy type 2 (DM2). Neuromuscular Disorders, 14(4), 274-283.