P.07 Characterization of MRI brain abnormalities in X-linked myotubular myopathy

Abstract

X linked myotubular myopathy (XLMTM) is a rare, typically severe, congenital myopathy that often results in significant weakness from birth, with a need for mechanical ventilation and wheelchair assistance. It is caused by a mutation in the myotubularin (<i>MTM1</i>) gene, whose gene product plays an important role in muscle cell differentiation. In addition to the important role of MTM1 in skeletal muscle, there is emerging evidence that patients with XLMTM can have multisystem abnormalities, including liver concerns and cognitive impairment. An organ system of particular interest for us is the Central Nervous System (CNS). Brain involvement has been described in different neuromuscular disorders, though not typically in congenital myopathies. In contrast to other congenital myopathies, there are a handful of case reports and informal observations of structural brain abnormalities in XLMTM. However, there has not yet been a comprehensive review of neuroimaging features in XLMTM. We have developed a multi-site study, aiming to retrospectively gather brain MRI and relevant clinical information for patients with XLMTM around the world. Our goals are to define the relative prevalence of CNS structural anomalies in XLMTM and to describe the common features of brain MRIs from XLMTM patients. In particular, we hope to elucidate unifying or common changes amongst many patients, and whether they correlate with birth-related injury, genotype, clinical phenotype, long-term outcome, or survival. We hypothesize that there is unrecognized brain involvement XLMTM, as will be reflected by brain MRI findings, and that these changes will correlate with both clinical outcomes and the degree of illness/adversity. In addition to study design, we will present our findings from the first cases collected for the study.