Respiratory Muscle Function in Untreated X-Linked Myotubular Myopathy (XLMTM)

Study Overview
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Brief Summary
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This study is a longitudinal study evaluating the severity and progression of respiratory muscle function in patients with X-Linked Myotubular Myopathy (XLMTM) aged 0-14.

Detailed Description
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Subjects aged 0-7 will be evaluated every six months for a total of three evaluations (Baseline, Six-Month Visit, Twelve-Month Visit). Subjects aged 8-14 will be evaluated every twelve months for a total of two evaluations (Baseline, Twelve-Month Visit). Evaluations include medical history, physical exam, respiratory muscle tests, a qualitative interview related to the child's function and use of respiratory aids, and quality of life assessments.

Official Title
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Respiratory Muscle Function in Untreated X-Linked Myotubular Myopathy (XLMTM)

Conditions
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X-linked Myotubular Myopathy

Intervention / Treatment
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* Other: History and physical
* Other: Tidal breathing
* Other: Maximal respiratory pressures
* Other: Peak cough flow
* Other: Pediatric Evaluation of Disability Inventory
* Other: PedsQL Multidimensional Fatigue Scale
* Other: Review of ventilation requirements


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients who have centronuclear myopathy resulting from an MTM1 genetic mutation. Patients who are between 0 and 14 years of age. Exclusion Criteria: Patients without a confirmed genetic mutation. Patients unable to travel to the site for the study. Patients participating in an interventional treatment study for XLMTM at the time of enrollment. Patients who are unable to complete study procedures. Patients who have a condition that, in the opinion of the investigator, would make participation in this study unsafe.

Ages Eligible for Study
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Maximum Age: 14 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Males with X-linked myotubular myopathy<br>History and physical, Tidal breathing, Maximal respiratory pressures, Peak cough flow, Pediatric Evaluation of Disability Inventory, PedsQL Multidimensional Fatigue Scale, Review of ventilation requirements | Other: History and physical<br>* Subjects will undergo a physical exam and medical history review, including review of genetic test results.<br>Other: Tidal breathing<br>* Subjects' breathing patterns will be evaluated at rest and at reduced/eliminated ventilator support.<br>Other: Maximal respiratory pressures<br>* Subjects' strongest inspiratory and expiratory pressures will be measured.<br>* Other names: MIP, MEP;Other: Peak cough flow<br>* Subjects' strongest coughs will be measured.<br>Other: Pediatric Evaluation of Disability Inventory<br>* Assesses the functional capabilities of children with disabilities.<br>* Other names: PEDI;Other: PedsQL Multidimensional Fatigue Scale<br>* Assesses general fatigue, sleep/rest fatigue, and cognitive fatigue.<br>Other: Review of ventilation requirements<br>* Subjects's use of mechanical ventilation reviewed by the study team.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in baseline visit off-ventilator tolerance at 6 month visit and 12 month visit. |  | Change in baseline visit, at 6 month visit and 12 month visit | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in baseline visit maximal respiratory pressures at 6 month visit, and 12 month visit. | Subject's maximal inspiratory and expiratory pressures. | Change in baseline visit, at 6 month visit and 12 month visit | 
| Change in baseline peak cough flow at 6 month visit and 12 month visit. | Subjects will be assessed on the ability to generate a cough and the strength of that cough. | Change in baseline visit, at 6 month visit and 12 month visit | 
| Change in baseline tidal breathing at 6 month visit and 12 month visit. | Subject's resting breathing pattern will be assessed. | Change in baseline visit, at 6 month visit and 12 month visit | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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myotubular myopathy, respiratory muscles, natural history