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X-Linked Myotubular Myopathy

National Organization for Rare Disorders, Inc.

Important

It is possible that the main title of the report X-Linked Myotubular Myopathy 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

  • MTM
  • myotubular myopathy
  • XLCNM
  • x-linked centronuclear myopathy
  • XLMTM

Disorder Subdivisions

  • None

General Discussion

Summary

X-linked myotubular myopathy (XLMTM) is a rare genetic neuromuscular disorder that is characterized by muscle weakness that can range from mild to profound. Symptoms are often present at birth, but may first develop during infancy or early childhood. In rare cases, symptoms may not develop until later, even adulthood. Common symptoms include mild to profound muscle weakness, diminished muscle tone (hypotonia or "floppiness"), feeding difficulties, and potentially severe breathing complications (respiratory distress). Feeding difficulties and respiratory distress develop because of weakness of the muscles that are involved in swallowing and breathing. The overall severity of the disorder can range from mildly affected individuals to individuals who develop severe, life-threatening complications during infancy and early childhood. Most affected individuals have a severe form of the disorder and respiratory failure is an almost uniform occurrence. XLMTM is caused by mutations to the myotubularin (MTM1) gene. The disorder is inherited as an X-linked recessive condition. The disorder predominantly affects males, but female carriers can develop mild symptoms. In rare specific cases, females can develop a severe form similar to that seen in males.



Introduction

XLMTM belongs to a larger group of disorders known as the centronuclear myopathies. In addition to XLMTM, there are forms of centronuclear myopathy that are inherited as autosomal dominant or autosomal recessive conditions. Generally, the autosomal forms are less severe than XLMTM, however, in rare cases, individuals with an autosomal form can develop severe complications that are similar to those seen in XLMTM. Centronuclear myopathies derive their name from the abnormal location of the nucleus in the center of the muscle fiber (muscle cell) rather than its normal position on the edge. Additional pathologic features include disorganized perinuclear organelles and abnormalities in oxidative staining patterns. Centronuclear myopathies can be further classified into the larger, broader category of congenital myopathy, a group of genetic muscle disorders that are present at birth.



In the medical literature, centronuclear myopathy is generally used for the autosomal forms of the disorder and myotubular myopathy is generally used for the X-linked form. Distinguishing between the X-linked (myotubular) form and the autosomal forms is essential as the symptoms are usually more severe in the X-linked form. NORD has a separate report on centronuclear myopathy that describes the autosomal forms in greater detail. This report specifically deals with X-linked centronuclear (myotubular) myopathy.

Resources

CLIMB (Children Living with Inherited Metabolic Diseases)

Climb Building

176 Nantwich Road

Crewe, CW2 6BG

United Kingdom

Tel: 4408452412173

Fax: 4408452412174

Email: enquiries@climb.org.uk

Internet: http://www.CLIMB.org.uk



Myotubular Myopathy Resource Group

2602 Quaker Drive

Texas City, TX 77590

Tel: (409)945-8569

Email: info@mtmrg.org

Internet: http://www.mtmrg.org



Contact A Family

209-211 City Road

London, EC1V 1JN

United Kingdom

Tel: 02076088700

Fax: 02076088701

Tel: 08088083555

Email: info@cafamily.org.uk

Internet: http://www.cafamily.org.uk/



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 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 Neurological Disorders and Stroke

P.O. Box 5801

Bethesda, MD 20824

Tel: (301)496-5751

Fax: (301)402-2186

Tel: (800)352-9424

TDD: (301)468-5981

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



European Alliance of Neuromuscular Disorders Associations

MDG Malta 4

Gzira Road

Gzira, GAR 04

Malta

Tel: 0035621346688

Fax: 0035621318024

Email: eamda@hotmail.com

Internet: http://www.eamda.net



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/



Cure CMD (Congenital Muscular Dystrophy)

P.O. Box 701

Olathe, KS 66051

USA

Tel: (866)400-3626

Email: info@curecmd.com

Internet: http://www.curecmd.org



Joshua Frase Foundation

222 Forbes Rd.

Suite 207

Braintree, MA 02184

Tel: (904)273-9818

Fax: (904)607-1358

Email: info@joshuafrase.org

Internet: www.joshuafrase.org



Myotubular Trust

15a Barnard Road

London SW11 1QT

Tel: 07518 113692

Email: contact@myotubulartrust.org

Internet: http://www.myotubulartrust.org



For a Complete Report

This is an abstract of a report from the National Organization for Rare Disorders (NORD). A copy of the complete report can be downloaded free from the NORD website for registered users. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational therapies (if available), and references from medical literature. For a full-text version of this topic, go to MyD-H, the Dartmouth-Hitchcock patient portal. You must be a registered MyD-H user for the Lebanon, Manchester, or Nashua locations to access this site.

The information provided in this report is not intended for diagnostic purposes. It is provided for informational purposes only. NORD recommends that affected individuals seek the advice or counsel of their own personal physicians.

It is possible that the title of this topic is not the name you selected. Please check the Synonyms listing to find the alternate name(s) and Disorder Subdivision(s) covered by this report

This disease entry is based upon medical information available through the date at the end of the topic. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder.

For additional information and assistance about rare disorders, please contact the National Organization for Rare Disorders at P.O. Box 1968, Danbury, CT 06813-1968; phone (203) 744-0100; web site www.rarediseases.org or email orphan@rarediseases.org

Last Updated:  3/19/2013

Copyright  1994, 1996, 2005, 2013 National Organization for Rare Disorders, Inc.

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