Congenital Myasthenic Syndrome

What is Congenital Myasthenic Syndrome?

Congenital myasthenic syndrome (CMS) is a group of inherited neuromuscular disorders that cause muscle weakness and fatigue. It is caused by a genetic mutation, or abnormality, that affects the functioning of the transmission of nerve impulses to the muscles. Symptoms usually begin in infancy or childhood, but may also be seen in adults. CMSN usually affects the musculoskeletal system, but can also affect other body systems, including eyes, ears, respiratory and autonomic nervous systems.

People with CMSN may experience a range of symptoms, including muscle weakness and fatigue, difficulty walking, speaking or swallowing, or breathing problems. These symptoms can worsen over time, or may be very mild and hardly noticeable. CMS can also affect other bodily functions, depending on which gene is affected.

Symptoms of Congenital Myasthenic Syndrome

The symptoms of CMS vary greatly from person to person, depending on the gene affected and the severity of the condition. Common symptoms include:

  • Muscle weakness, often affecting the facial muscles, arms, and legs
  • Difficulty walking, speaking or swallowing
  • Fatigue
  • Respiratory problems, such as difficulty breathing
  • Decreased reflexes
  • Drooping eyelids or eyes
  • Problems with coordination or balance
  • Problems with vision or hearing

Diagnosis of Congenital Myasthenic Syndrome

A diagnosis of CMS can often be made after a physical examination and analysis of family history. Your doctor may also recommend a muscle biopsy or blood tests to help confirm the diagnosis. In some cases, an electromyography (EMG) or nerve conduction studies may also be recommended.

Treatment of Congenital Myasthenic Syndrome

Treatment of CMS is tailored to the individual and depends upon the severity of the condition. Common treatments include:

  • Medications to manage symptoms, such as anticholinesterase drugs or immunosuppressants
  • Intravenous immunoglobulin therapy
  • Gene therapy
  • Physical therapy
  • Occupational therapy
  • Coordinated care with various specialists

It is important to note that there is no cure for CMS. Treatment is aimed at managing and improving symptoms to allow a person to maintain a good quality of life.