Hereditary muscular atrophy of peroneal type, also known as Charcot-Marie-Tooth disease type 4 (CMT4), is a genetic disorder that affects the peripheral nerves, leading to muscle weakness and wasting, primarily in the lower legs and feet. It is classified as a peripheral neuropathy, which implies damage to the peripheral nerves that extend from the spinal cord to the muscles.
This condition is inherited in an autosomal recessive manner, meaning that an affected individual must inherit two copies of the defective gene, one from each parent, to develop the disease. The specific genetic mutations associated with CMT4 affect proteins involved in the structure and function of peripheral nerves.
The main symptoms include progressive muscle weakness and wasting, particularly in the muscles surrounding the shinbone (peroneal muscles). This can lead to foot drop, weakness in ankle muscles, and a high-stepped or "slapping" gait. Sensory abnormalities such as numbness, tingling, and decreased sensation in the feet and lower legs may also be present.
Diagnosis of hereditary muscular atrophy of peroneal type often involves a thorough clinical evaluation, nerve conduction studies, electromyography, and genetic testing to confirm the presence of specific genetic mutations. Currently, there is no cure for CMT4, and treatment mainly focuses on managing symptoms and maintaining functionality through physical therapy, orthopedic interventions (braces or splints), and pain management.
Overall, hereditary muscular atrophy of peroneal type is a genetic disorder characterized by progressive muscle weakness and wasting primarily in the lower legs and feet, caused by specific genetic mutations affecting peripheral nerves.
