Limb girdle muscular dystrophy

Limb Girdle Muscular Dystrophy Limb Girdle Muscular Dystrophy (LGMD) refers to a group of genetically inherited disorders characterized by progressive muscle weakness and wasting, primarily affecting the shoulder and pelvic girdle muscles. This condition is part of the larger family of muscular dystrophies, which are diseases that cause muscle degeneration and weakness.

Classification

LGMD is classified based on the genetic cause and the mode of inheritance. The two main types are:

• Autosomal Dominant LGMD (LGMD1): This type is less common and is inherited in an autosomal dominant pattern, meaning only one copy of the mutated gene is sufficient to cause the disorder.
• Autosomal Recessive LGMD (LGMD2): This type is more common and requires two copies of the mutated gene, one from each parent, to manifest the disease.

Each type is further subdivided based on the specific gene mutation involved. For example, LGMD2A is caused by mutations in the CAPN3 gene, while LGMD2B is due to mutations in the DYSF gene.

Symptoms

The symptoms of LGMD can vary widely depending on the specific type and severity of the disease. Common symptoms include:

• Progressive muscle weakness, particularly in the hips, thighs, shoulders, and upper arms.
• Difficulty walking, running, or climbing stairs.
• Muscle wasting and atrophy.
• Joint contractures and scoliosis in some cases.
• Cardiopulmonary complications in advanced stages.

Diagnosis

Diagnosing LGMD involves a combination of clinical evaluation, family history, and specialized tests, including:

• Genetic Testing: To identify specific gene mutations associated with LGMD.
• Muscle Biopsy: To examine muscle tissue for characteristic changes.
• Electromyography (EMG): To assess the electrical activity of muscles.
• Blood Tests: To measure levels of creatine kinase (CK), an enzyme that leaks out of damaged muscle.

Treatment

Currently, there is no cure for LGMD, but treatment focuses on managing symptoms and improving quality of life. Treatment options include:

• Physical Therapy: To maintain muscle strength and flexibility.
• Occupational Therapy: To assist with daily activities and improve independence.
• Orthopedic Devices: Such as braces or wheelchairs to aid mobility.
• Medications: Corticosteroids may be used in some cases to slow muscle degeneration.
• Cardiac and Respiratory Care: Regular monitoring and treatment for heart and lung complications.

Research and Future Directions

Research into LGMD is ongoing, with efforts focused on understanding the genetic basis of the disease and developing potential therapies. Gene therapy, exon skipping, and stem cell therapy are areas of active investigation.

See Also

• Muscular Dystrophy
• Genetic Disorders
• Neuromuscular Diseases
• "Limb Girdle Muscular Dystrophy." National Institute of Neurological Disorders and Stroke. [1]
• "Muscular Dystrophy Association." [2]

NIH genetic and rare disease info

• NIH info on Limb girdle muscular dystrophy

Limb girdle muscular dystrophy is a rare disease.