You are here: Home / Rare Disease Information / Rare Disease Database

Search Rare Diseases

Enter a disease name or synonym to search NORD's database of reports.

0-9 - A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z

Myotonia Congenita

Abstract

You are reading a NORD Rare Disease Report Abstract. NORD’s full collection of reports on over 1200 rare diseases is available to subscribers (click here for details). We are now also offering two full rare disease reports per day to visitors on our Web site.

Synonyms of Myotonia Congenita

  • No synonyms found.

Disorder Subdivisions

  • Becker Disease; Myotonia Congenita, Autosomal Recessive (MCR); Generalized
  • Thomsen Disease (THD); Myotonia Congenita, Autosomal Dominant

General Discussion

Myotonia congenita is a rare genetic disorder in which an abnormality of voluntary (skeletal) muscle fiber membranes causes an unusually exaggerated response to stimulation (hyperexcitability). As a result, affected individuals have difficulty relaxing certain muscles after contracting them (myotonia), muscle stiffness (rigidity), and associated symptoms. Such symptoms tend to occur when attempting to move certain muscles after rest. In many cases, individuals with myotonia congenita also have abnormal enlargement of the muscles (hypertrophy), resulting in a "herculean" or "body-builder like" appearance.

Two main forms of myotonia congenita have been described: Thomsen disease and Becker disease. In individuals with Thomsen disease, symptoms and findings such as myotonia, associated muscle rigidity, and abnormal muscle enlargement may become apparent from infancy to approximately two to three years of age. In many cases, muscles of the eyelids, hands, and legs may be most affected. Thomsen disease is transmitted as an autosomal dominant trait.

In those with Becker disease, symptoms most commonly become apparent between the ages of four and 12 years. As in Thomsen type myotonia congenita, affected individuals develop myotonia, associated muscle rigidity, and abnormal muscle enlargement (hypertrophy). The symptoms tend to remain constant, with little progression. Becker disease is inherited as an autosomal recessive trait.

Myotonia Congenita Resources

(Please note that some of these organizations may provide information concerning certain conditions potentially associated with this disorder [e.g., myotonia, risk for malignant hyperthermia or an MH-like condition, etc.].)

Organizations:

The information in NORD’s Rare Disease Database is for educational purposes only. It should never be used for diagnostic or treatment purposes. If you have questions regarding a medical condition, always seek the advice of your physician or other qualified health professional. NORD’s reports provide a brief overview of rare diseases. For more specific information, we encourage you to contact your personal physician or the agencies listed as “Resources” on this report.

0-9 - A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z

NORD's Rare Disease Information Database is copyrighted and may not be published without the written consent of NORD.

 
Copyright ©2014 NORD - National Organization for Rare Disorders, Inc. All rights reserved.
The following trademarks/registered service marks are owned by NORD: NORD, National Organization for Rare Disorders, the NORD logo, RareConnect. .