autosomal recessive limb-girdle muscular dystrophy type 2M

Autosomal recessive limb-girdle muscular dystrophy type 2M is a neuromuscular disorder characterized by muscle weakness primarily affecting the limb-girdle and axial regions. It is caused by pathogenic variants in the FKTN gene, which plays a crucial role in maintaining muscle structure and function. The condition typically presents in infancy, with early signs including hypotonia and motor delays, and may worsen following febrile illnesses. It is very rare, affecting fewer than 1 in a million people, and the severity of symptoms can vary considerably among individuals.

Individuals with this condition consistently experience motor delays, hypotonia, and proximal muscle weakness, along with elevated creatine kinase levels, which are clear indicators of muscular dystrophy. Early symptoms often include difficulties in achieving motor milestones, while later features can include progressive weakness and, in some cases, calf muscle hypertrophy, frequent falls, and scapular muscle atrophy. Not all individuals experience all features, and severity varies considerably, making personalized assessment important for optimal care.

The condition is caused by pathogenic variants in the FKTN gene and is inherited in an autosomal recessive manner, meaning that affected individuals inherit two altered copies of the gene. It is more common when parents share a common ancestor, as this increases the likelihood that both carry the same rare genetic variant. This genetic basis underscores the importance of molecular genetic testing and genetic counseling for families looking to understand the risks and explore carrier testing options.

Management focuses on supportive care and symptom management because there are no FDA-approved treatments specifically for this condition. Treatment is individualized and typically involves a multidisciplinary team, including physical and occupational therapists, to help maintain muscle function and mobility. Genetic counseling is recommended to help families understand inheritance patterns and explore family planning options.

The long-term outlook for autosomal recessive limb-girdle muscular dystrophy type 2M is highly variable, with outcomes depending on the severity of muscle involvement and the level of supportive care provided. Many individuals experience significant challenges early in life, but with current standards of care, symptoms may stabilize and allow for a reasonable quality of life, although some may experience further decline later on. Outcomes described in medical literature continue to evolve as standards of care improve, and families often find it helpful to connect with neuromuscular specialists and support groups for ongoing guidance.

Clinical trials are underway exploring new treatment approaches for this condition. Individuals interested in clinical trials can search ClinicalTrials.gov or consult their care team about eligibility.