E-Pearl of the Week: Myotonia Congenita

June 12, 2012


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June 12, 2012

Myotonia Congenita

Myotonia Congenita is a chloride ion channelopathy of muscle, with symptoms including delayed relaxation of the muscles after voluntary contraction (myotonia), stiffness, muscle hypertrophy, pain, cramping, and transient weakness with some mutations. The disorder is caused by a genetic mutation involving the chloride channel of the muscles. In addition to humans, it is also seen in some goats, canines and horses. Read more about the importance of exon deletions and duplications in the CLCN1 gene in the analysis of recessive cases of Myotonia Congenita in this week's issue of Neurology.


1.  Rayan DLR, Haworth A, Sud R. A new explanation for recessive Myotonia Congenita – exon deletions and duplications in CLCN1.  Neurology 2012; 78: 1953–1958.
2.  Lossin C, George AL . Myotonia congenita. Adv Genet 2008; 63:25–55.

Submitted by: Stacey L. Clardy, MD, PhD

Disclosure: Dr. Clardy serves on the editorial team for the Neurology® Resident and Fellow Section.

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