A Clinical Assessment Study in X-Linked Myotubular Myopathy (XLMTM) Subjects

Inclusion Criteria

• •Subject has a diagnosis of XLMTM resulting from a confirmed mutation in the MTM1 gene
• •Subject is male
• •Subject is aged less than 4 years
• •Subject requires some mechanical ventilatory support (eg, ranging from 24 hours per day full time mechanical ventilation, to noninvasive support such as continuous positive airway pressure \[CPAP\] or bilevel positive airway pressure \[BiPAP\] during sleeping hours)
• •Access to subject's medical records
• •Signed informed consent by the parent(s) or legally authorized representative(s) (LAR) (when applicable)
• •Subject and parent(s) or LAR are willing and able to comply with study visits and study procedures