Prospective, Longitudinal Study of the Natural History and Functional Status of Patients With Myotubular Myopathy (MTM)

This is a prospective, non-interventional, longitudinal study of the natural history and function of patients with MTM. The study duration is 36 months. The enrollment period will be 12 months and each patient will be assessed over 24 months. Data will be analyzed at baseline and annually thereafter and reports will be prepared based on these analyses. A final report will summarize findings after all patients have completed 24 months of follow-up. Assessments performed in this study will be based on the age and ambulatory status of the patient. The assessments will also be adjusted to account for the variability in both phenotypes and age of the patients who may participate in this study. Patients will be evaluated at Baseline, Month 6, Month 12 and Month 24. It is anticipated that approximately 60 patients from the United States, Canada and Europe will be included in this study.

Inclusion criteria

• Patients of any age (newborns included) may participate.
• Patients over 18 years of age and parent(s)/legal guardian(s) of patients <18 years of age must provide written informed consent prior to participating in the study and informed assent will be obtained from minors at least 7 years of age when required by regulation.
• MTM resulting from a mutation in the MTM1 gene.
• Male or symptomatic female. A symptomatic female will be defined by the motor function assessment by Motor Function Measure (MFM) or North Star Ambulatory Assessment (NSAA) below 80% of the total score.
• Willing and able to comply with all protocol requirements and procedures.

Exclusion criteria

• Other disease which may significantly interfere with the assessment of MTM and is clearly not related to the disease.
• Currently enrolled in a treatment study; or treatment with an experimental therapy other than pyridostigmine.