Paramyotonia Congenita

Paramyotonia Congenita

National Organization for Rare Disorders, Inc.

Important

It is possible that the main title of the report Paramyotonia Congenita is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.

Synonyms

  • Eulenburg Disease
  • Myotonia Congenita Intermittens
  • Paralysis Periodica Paramyotonica
  • Paramyotonia Congenita of Von Eulenburg
  • Von Eulenburg Paramyotonia Congenita

Disorder Subdivisions

  • None

General Discussion

Paramyotonia congenita is a rare muscular disorder inherited as an autosomal dominant trait. This nonprogressive disorder is characterized by a condition in which the muscles do not relax after contracting (myotonia). Symptoms can be triggered by exposure to the cold. There are also intermittent periods of a type of paralysis in which there is no muscle tone (flaccid paresis). This condition does not necessarily coincide with exposure to cold temperatures or myotonia. There is no wasting (atrophy) or increase in bulk (hypertrophy) of muscles with this disorder.

Symptoms

Symptoms include muscle stiffness and weakness, mostly in the face, neck and upper extremities. The muscles are slow to relax after contracting (myotonia). This condition may become worse with exposure to cold.



Paramyotonia congenita is usually apparent during infancy and is not progressive. Individuals with this disorder do not have wasting of muscles (atrophy) or an increase of muscle bulk (hypertrophy).

Causes

This condition is transmitted as an autosomal dominant genetic trait. The malfunctioning gene has been tracked to the long arm of chromosome 17 (17q23.1-q25.3)



Chromosomes, which are present in the nucleus of human cells, carry the genetic information for each individual. Human body cells normally have 46 chromosomes. Pairs of human chromosomes are numbered from 1 through 22 and the sex chromosomes are designated X and Y. Males have one X and one Y chromosome and females have two X chromosomes. Each chromosome has a short arm designated "p" and a long arm designated "q". Chromosomes are further sub-divided into many bands that are numbered. For example, "chromosome 17q23.1-q25.3" refers to a region on the long arm of chromosome 17 between bands 23.1 and 25.3. The numbered bands specify the location of the thousands of genes that are present on each chromosome.



Genetic diseases are determined by the combination of genes for a particular trait that are on the chromosomes received from the father and the mother.



All individuals carry a few abnormal genes. Parents who are close relatives (consanguineous) have a higher chance than unrelated parents to both carry the same abnormal gene, which increases the risk to have children with a recessive genetic disorder.



Dominant genetic disorders occur when only a single copy of an abnormal gene is necessary for the appearance of the disease. The abnormal gene can be inherited from either parent, or can be the result of a new mutation (gene change) in the affected individual. The risk of passing the abnormal gene from affected parent to offspring is 50% for each pregnancy regardless of the sex of the resulting child.

Affected Populations

Paramyotonia congenita is a very rare disorder that affects males and females in equal numbers. A detailed study conducted in Germany concluded that the incidence of PMC was between 1 in 180,000 and 1 in 350,000. They note that the distribution of this disorder is not uniform since they found a region of the country in which the incidence was 1 in 8000.



Three large families with multiple generations of affected members have accounted for at least 60 patients with paramyotonia congenita.

Standard Therapies

Diagnosis

When paramyotonia congenita is suspected, a test is administered to test the capacity of muscles to conduct electricity (electromyography).



Treatment

The aim of treatment is to reduce the intensity of acute symptoms and to prevent, as far as possible, further attacks. Some attacks are so mild that treatment is not necessary. However, in other instances drug therapy is required.



Some patients with paramyotonia congenita may benefit from acetazolamide or thiazide diuretic drugs to reduce the number of paralytic attacks. Treatment with the drug tocainide may help reduce the cold-induced symptoms in some patients.



Genetic counseling may be of benefit for patients and their families. Other treatment is symptomatic and supportive.

Investigational Therapies

Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. government funding, and some supported by private industry, are posted on this government web site.



For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:



Tollfree: (800) 411-1222

TTY: (866) 411-1010

Email: prpl@cc.nih.gov



For information about clinical trials sponsored by private sources, contact:

www.centerwatch.com

References

TEXTBOOKS

Kasper, DL, Fauci AS, Longo DL, et al., eds. Harrison's Principles of Internal Medicine. 16th ed. McGraw-Hill Companies. New York, NY; 2005:2526; 2537.



Rowland LP, ed. Merritt's Neurology. 10th ed. Lippincott Williams & Wilkins. Philadelphia, PA. 2000:749.



Rimoin D, Connor JM, Pyeritz RP, Korf BR, eds. Emory and Rimoin's Principles and Practice of Medical Genetics. 4th ed. Churchill Livingstone. New York, NY; 2002:3377-82.



JOURNAL ARTICLES

Weber MA, Nielles-Vallespin S, Huttner HB, Worhle JC, et al. Radiology. 2006;240:489-500.



Kurihara T. New classification and treatment for myotonic disorders. Intern Med. 2005;44:1027-32.



Vicart S, Sternberg D, Fontaine B, Meola G. Human skeletal muscle sodiym channelopathies. Neurol Sci. 2005;26:194-202



Fredericson M, Kim BJ, Date ES. Disabling foot cramping in a runner secondary to paramyotonia congenita: a case report. Foot Ankle Int. 2004;25



Kuntzer T. [Electrophysiological testing in muscle channelopathies] Rev Neurol (Paris). 2004;160(5 Pt 2):S49-54. French.



FROM THE INTERNET

McKusick VA, ed. Online Mendelian Inheritance in Man (OMIM). Baltimore, MD: The Johns Hopkins University Press; Paramyotonia Congenita of Von Eulenburg; PMC. Entry No: 168300; Last Edit: 8/26/2005.



Mosenkis A. Hyperkalemic periodic paralysis. Medical Encyclopedia. MedlinePlus. Update Date: 8/5/2004. 4pp.

www.nlm.nih.gov/medlineplus/ency/article/000316.htm



Frequently Asked Questions about Paramyotonia Congenita. Periodic Paralysis News Desk. Last updated March 2006. 4pp.

www.hkpp.org/faq/pmc.html



Emery AEH. Myotonias. Muscular Dystrophy Campaign. 2004. 3pp.

www.muscular-dystrophy.org/information_resources/factsheets/medical_conditions_factsheets/myotonias.html

Resources

Muscular Dystrophy Association

3300 East Sunrise Drive

Tucson, AZ 85718-3208

USA

Tel: (520)529-2000

Fax: (520)529-5300

Tel: (800)572-1717

Email: mda@mdausa.org

Internet: http://www.mda.org/



Muscular Dystrophy Canada

2345 Yonge Street Suite 900

Toronto

Ontario, M4P 2E5

Canada

Tel: 4164880030

Fax: 4164887523

Tel: 866MUSCLE8

Email: info@muscle.ca

Internet: http://www.muscle.ca



Muscular Dystrophy Campaign

61 Southwark Street

London, SE1 0HL

United Kingdom

Tel: 02078034800

Email: info@muscular-dystrophy.org

Internet: http://www.muscular-dystrophy.org



NIH/National Institute of Arthritis and Musculoskeletal and Skin Diseases

Information Clearinghouse

One AMS Circle

Bethesda, MD 20892-3675

USA

Tel: (301)495-4484

Fax: (301)718-6366

Tel: (877)226-4267

TDD: (301)565-2966

Email: NIAMSinfo@mail.nih.gov

Internet: http://www.niams.nih.gov/



Muscular Dystrophy Association of New Zealand, Inc.

PO Box 16-238

Sandringham

Auckland,

New Zealand

Tel: 098150247

Fax: 092777540

Tel: 0800800337

Email: info@mda.org.nz

Internet: http://www.mda.org.nz/



Muscular Dystrophy Australia

111 Boundary Road

North Melbourne

VIC 3051

Australia

Tel: 61393209555

Fax: 61393209595

Tel: 1800656632

Email: info@mda.org.au

Internet: http://www.mda.org.au



Genetic and Rare Diseases (GARD) Information Center

PO Box 8126

Gaithersburg, MD 20898-8126

Tel: (301)251-4925

Fax: (301)251-4911

Tel: (888)205-2311

TDD: (888)205-3223

Internet: http://rarediseases.info.nih.gov/GARD/



Child Neurology Foundation

2000 West 98th Street

Bloomington, MN 55431

USA

Tel: (952)641-6100

Fax: (952)881-6276

Tel: (877)263-5430

Email: jstone@childneurologyfoundation.org

Internet: http://www.childneurologyfoundation.org



For a Complete Report

This is an abstract of a report from the National Organization for Rare Disorders, Inc.® (NORD). Cigna members can access the complete report by logging into myCigna.com. For non-Cigna members, a copy of the complete report can be obtained for a small fee by visiting the NORD website. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational treatments (if available), and references from medical literature. For a full-text version of this topic, see http://www.rarediseases.org/search/rdblist.html.

This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use . How this information was developed to help you make better health decisions.

Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.