Myotubular myopathy (MTM) is a rare genetic neuromuscular disorder that occurs exclusively in males. Symptoms include muscle weakness and diminished muscle tone, and usually present in the first year of infancy, but can also develop and present later in childhood. It is a life threatening disorder, with patients needing support from health and social care services. Due to the rarity of the disorder, there is limited understanding of MTM patients and their practical management in the health care system.
This study aims to understand the real world management of MTM. We will describe the proportion of males in the general population who have been diagnosed with MTM in the last twenty years, and report how often patients use resources in primary care and secondary care for MTM related events.
Myotubular myopathy (MTM) is an X-linked monogenic disorder characterized by profound skeletal muscle weakness, impaired motor function, severe respiratory failure and death. It is caused by mutations in the MTM1 gene which results in deficiencies in myotubularin and disrupts normal development, maintenance and function of skeletal muscle. It occurs almost entirely in males and in its most severe form 50% of babies will die in their first year of life. Those who survive are likely to be dependent on ventilator support; most patients never achieve ambulation.
There has been limited reporting on the real world epidemiology and management of patients with MTM, in part due to the rarity of the disorder.
This study aims to provide foundational insights on the prevalence, incidence, health care resource use (HCRU), associated costs, and mortality of males with MTM. Cases will be identified using diagnosis codes , and will be described in terms of their patient characteristics and a-priori comorbidities. The prevalence and incidence rate of MTM among the general population of males will be estimated. The HCRU of MTM cases will include a reporting of resource use in primary care, outpatient setting, inpatient setting and A&E. We will estimate associated costs of HCRU. Mortality of MTM cases will also be described.
This is a descriptive study using the most recent 20 years of linked electronic medical records in England.
Health Outcomes to be Measured:
MTM cases (for prevalence and incidence calculations); Healthcare resource use including number of GP visits, hospital outpatient visits, inpatient admissions, A&E visits, diagnostic tests, procedures, and length of stay in hospital; Costs for healthcare resource use; All-cause mortality and cause-specific mortality.
HES Accident and Emergency;HES Admitted Patient Care;HES Outpatient;ONS Death Registration Data