What causes Paramyotonia congenita?
Mutations in the SCN4A gene cause paramyotonia congenita. This gene provides instructions for making a protein that is critical for the normal function of skeletal muscle cells. For the body to move normally, skeletal muscles must tense (contract) and relax in a coordinated way.
Is myotonia congenita a form of muscular dystrophy?
Myotonia congenita is a congenital neuromuscular channelopathy that affects skeletal muscles (muscles used for movement). It is a genetic disorder….
| Myotonia congenita | |
|---|---|
| Differential diagnosis | Myotonic dystrophy, Paramyotonia congenita |
| Treatment | Physiotherapy, medication |
What are the symptoms of myotonia congenita?
Myotonia congenita is a genetic disease characterized by the inability of the skeletal muscles to quickly relax after voluntary movements. Symptoms typically begin in childhood and vary from person to person. They may include muscle stiffness, muscle weakness, and attacks of weakness brought on by movement after rest.
What causes myotonic discharges on EMG?
Electrical myotonia is the spontaneous discharge of muscle fibers that waxes and wanes in both amplitude and frequency on electromyography (EMG). Myotonia is thought to be due to increased excitability of muscle fibers, leading to discharge of repetitive action potentials in response to stimulation.
Can people have myotonia congenita?
Myotonia congenita is estimated to affect 1 in 100,000 people worldwide. This condition is more common in northern Scandinavia, where it occurs in approximately 1 in 10,000 people.
Is myotonia congenita a disability?
The disease progresses slowly until 30 to 40 years of age and then appears to stabilize. The legs are more severely involved than the face or arms, and severe myotonia of the lower extremities may result in disability. Severe myotonic episodes may be associated with transient muscle weakness, especially in the hands.
Does myotonia congenita get worse with age?
Though myotonia congenita starts in childhood, it usually doesn’t get worse over time. You or your child should be able to lead a normal, active life with this condition. The muscle stiffness can affect movements like walking, chewing, and swallowing, but exercise and medicine can help.