GTR Home > Conditions/Phenotypes > Severe X-linked myotubular myopathy


Excerpted from the GeneReview: X-Linked Centronuclear Myopathy
X-linked centronuclear myopathy (XLCNM) (also known as myotubular myopathy [MTM]) is characterized by muscle weakness that ranges from severe to mild. Severe (classic) XLCNM presents prenatally with polyhydramnios and decreased fetal movement and in newborns with weakness, hypotonia, and respiratory distress. Affected males have significantly delayed motor milestones and most fail to achieve independent ambulation. Weakness is profound and often involves facial and extraocular muscles. Respiratory failure is nearly uniform, with most affected individuals requiring 24-hour ventilatory assistance. A minority of males with severe XLCNM die in infancy. Males with moderate XLCNM achieve motor milestones more quickly than males with the severe form; about 40% require no ventilator support or intermittent support. Males with mild XLCNM may require ventilatory support only in the newborn period; they have minimally delayed motor milestones, are able to walk, and may lack myopathic facies. The muscle disease of XLCNM is not obviously progressive. Female carriers of XLCNM are generally asymptomatic, although rare manifesting heterozygotes have been described.

Available tests

51 tests are in the database for this condition.

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Genes See tests for all associated and related genes

  • Also known as: CNM, MTMX, XLMTM, MTM1
    Summary: myotubularin 1

Clinical features


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Suggested reading

  • Frase, 2016
    Dream On: The Pursuit to Cure Myotubular Myopathy Born out of a Mother's Vision

Practice guidelines

  • EuroGenetest, 2012
    Clinical utility gene card for: Centronuclear and myotubular myopathies.

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