National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

X-linked myotubular myopathy



Other Names:
X-linked centronuclear myopathy; XLCNM; XLMTM
Categories:
This disease is grouped under:

X-linked myotubular myopathy (XLMTM) is a type of centronuclear myopathy, which is a group of rare, inherited conditions that affect the muscles. XLMTM, specifically, occurs almost exclusively in males and is characterized by progressive muscle weakness (myopathy) and decreased muscle tone (hypotonia) that can range from mild to severe. The muscle problems impair the development of motor skills such as sitting, standing, and walking, and may disrupt primary functions such as breathing and feeding.[1][2] XLMTM is caused by changes (mutations) in the MTM1 gene and is inherited in an X-linked recessive manner.[1] Treatment is based on the signs and symptoms present in each person and may include physical and/or occupational therapy and assistive devices to help with mobility, eating and/or breathing.[2]
Last updated: 8/6/2015

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
30%-79% of people have these symptoms
Areflexia
Absent tendon reflexes
0001284
Atrioventricular block
Interruption of electrical communication between upper and lower chambers of heart
0001678
Cavernous hemangioma
Collection of dilated blood vessels that forms mass
0001048
EMG abnormality 0003457
External ophthalmoplegia
Paralysis or weakness of muscles within or surrounding outer part of eye
0000544
Gait disturbance
Abnormal gait
Abnormal walk
Impaired gait
[ more ]
0001288
Head tremor 0002346
Mask-like facies
Expressionless face
Lack of facial expression
Mask-like facial appearance
[ more ]
0000298
Muscular hypotonia
Low or weak muscle tone
0001252
Ptosis
Drooping upper eyelid
0000508
Respiratory failure requiring assisted ventilation 0004887
Scoliosis 0002650
Seizure 0001250
Skeletal muscle atrophy
Muscle degeneration
Muscle wasting
[ more ]
0003202
Percent of people who have these symptoms is not available through HPO
Arachnodactyly
Long slender fingers
Spider fingers
[ more ]
0001166
Birth length greater than 97th percentile 0003517
Cryptorchidism
Undescended testes
Undescended testis
[ more ]
0000028
Decreased fetal movement
Less than 10 fetal movements in 12 hours
0001558
Decreased liver function
Liver dysfunction
0001410
Diaphragmatic eventration 0009110
Facial palsy
Bell's palsy
0010628
Flexion contracture
Flexed joint that cannot be straightened
0001371
Generalized muscle weakness 0003324
High palate
Elevated palate
Increased palatal height
[ more ]
0000218
Hydrocephalus
Too much cerebrospinal fluid in the brain
0000238
Hypokinesia
Decreased muscle movement
Decreased spontaneous movement
Decreased spontaneous movements
[ more ]
0002375
Long face
Elongation of face
Increased height of face
Increased length of face
Vertical elongation of face
Vertical enlargement of face
Vertical overgrowth of face
[ more ]
0000276
Macrocephaly
Increased size of skull
Large head
Large head circumference
[ more ]
0000256
Narrow face
Decreased breadth of face
Decreased width of face
[ more ]
0000275
Neck muscle weakness
Floppy neck
0000467
Neonatal respiratory distress
Infantile respiratory distress
Newborn respiratory distress
Respiratory distress, neonatal
[ more ]
0002643
Polyhydramnios
High levels of amniotic fluid
0001561
Pyloric stenosis 0002021
Respiratory failure 0002878
Severe muscular hypotonia
Severely decreased muscle tone
0006829
Slender toe
Narrow toe
0011308
X-linked recessive inheritance 0001419
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Last updated: 7/1/2020

Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

Related diseases are conditions that have similar signs and symptoms. A health care provider may consider these conditions in the table below when making a diagnosis. Please note that the table may not include all the possible conditions related to this disease.

Conditions with similar signs and symptoms from Orphanet
The main differential diagnoses include congenital myotonic dystrophy and other conditions characterized by severe neonatal hypotonia (see these terms).
Visit the Orphanet disease page for more information.

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • ClinicalTrials.gov lists trials that are related to X-linked myotubular myopathy. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

Patient Registry


Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease


Living with a genetic or rare disease can impact the daily lives of patients and families. These resources can help families navigate various aspects of living with a rare disease.

Financial Resources


These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

In-Depth Information

  • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss X-linked myotubular myopathy. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know.


  1. X-linked myotubular myopathy. Genetics Home Reference. July 2014; http://ghr.nlm.nih.gov/condition/x-linked-myotubular-myopathy.
  2. Das S, Dowling J, Pierson CR. X-Linked Centronuclear Myopathy. GeneReviews. October 6, 2011; http://www.ncbi.nlm.nih.gov/books/NBK1432/.