Scapuloperoneal myopathy

Scapuloperoneal myopathy is a rare neuromuscular disease characterized by progressive weakness and wasting of the muscles in the shoulder (scapular) and lower legs (peroneal) areas. This condition is part of a group of muscle diseases known as myopathies, which affect the skeletal muscles used for movement. Scapuloperoneal myopathy can be inherited in various patterns, including autosomal dominant, autosomal recessive, and X-linked forms, depending on the specific genetic mutation involved.

Symptoms

The primary symptoms of scapuloperoneal myopathy include muscle weakness and atrophy in the shoulders and lower legs. This weakness can lead to difficulty with tasks that involve lifting the arms above the head or walking. In some cases, individuals may also experience muscle stiffness, cramps, and occasional muscle pain. The onset of symptoms can vary widely among affected individuals, ranging from early childhood to late adulthood.

Causes

Scapuloperoneal myopathy is caused by genetic mutations that affect muscle function. The specific genes involved can vary, leading to different forms of the disease. Some identified genes include FLNC (filamin C), which is associated with an autosomal dominant form of the condition, and EMD (emerin), linked to an X-linked form. The genetic diversity contributes to the variability in symptoms and inheritance patterns seen in scapuloperoneal myopathy.

Diagnosis

Diagnosis of scapuloperoneal myopathy involves a combination of clinical evaluation, family history, and genetic testing. Muscle biopsy may also be performed to examine the muscle tissue for characteristic changes associated with the disease. Electromyography (EMG) and nerve conduction studies can help assess muscle and nerve function, providing additional diagnostic information.

Treatment

There is currently no cure for scapuloperoneal myopathy, and treatment focuses on managing symptoms and improving quality of life. Physical therapy and occupational therapy can help maintain muscle strength and flexibility, while orthotic devices may be used to support weakened limbs. In some cases, surgery may be necessary to correct contractures or other skeletal abnormalities caused by muscle weakness.

Prognosis

The prognosis for individuals with scapuloperoneal myopathy varies depending on the severity of symptoms and the specific genetic mutation involved. While the condition can significantly impact mobility and daily activities, it is typically not life-threatening. Ongoing research into the genetic basis of scapuloperoneal myopathy may lead to new treatments and interventions in the future.