Clinical and genetic analysis of the first known Asian family with myotonic dystrophy type 2

Takahiro Nakayama, Harumasa Nakamura, Yasushi Oya, Takashi Kimura, Ichiro Imahuku, Kinji Ohno, Ichizo Nishino, Koji Abe, Tohru Matsuura

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)


Myotonic dystrophy type 2 (DM2) is more common than DM1 in Europe and is considered a rare cause of myotonic dystrophies in Asia. Its clinical course is also milder with more phenotypic variability than DM1. We herein describe the first known Asian family (three affected siblings) with DM2 based on clinical and genetic analyses. Notably, two of the affected siblings were previously diagnosed with limb-girdle muscular dystrophy. Myotonia (the inability of the muscle to relax) was absent or only faintly present in these individuals. The third sibling had grip myotonia and is the first known Asian DM2 patient. The three DM2 siblings share several systemic characteristics, including late-onset, proximal-dominant muscle weakness, diabetes, cataracts and asthma. Repeat-primed PCR across the DM2 repeat revealed a characteristic ladder pattern of a CCTG expansion in all siblings. Southern blotting analysis identified the presence of 3400 repeats. Further DM2 studies in Asian populations are needed to define the clinical presentation of Asian DM2 and as yet unidentified phenotypic differences from Caucasian patients.

Original languageEnglish
Pages (from-to)129-133
Number of pages5
JournalJournal of Human Genetics
Issue number3
Publication statusPublished - Mar 2014
Externally publishedYes


  • Asian
  • CCTG repeat
  • clinical spectrum
  • haplotype
  • limb-girdle muscular dystrophy
  • myotonia
  • myotonic dystrophy type 2 (DM2)

ASJC Scopus subject areas

  • Genetics
  • Genetics(clinical)


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