Facioscapulohumeral muscular dystrophy (FSHD) is a genetic disorder that affects the muscles of the face, shoulders, and upper arms. It is one of the most common forms of muscular dystrophy, with an estimated prevalence of 1 in 8,000 individuals worldwide. FSHD is caused by a genetic mutation that affects the expression of a protein called DUX4, which is normally suppressed in skeletal muscle.
The characteristic feature of FSHD is progressive weakness and wasting of the muscles in the face, shoulders, and upper arms. Symptoms typically appear in adolescence or early adulthood, and can range from mild weakness to severe disability. Facial weakness can cause difficulty with facial expressions, such as smiling or whistling. Shoulder weakness can cause difficulty raising the arms above the head, while weakness in the upper arms can make it difficult to perform tasks such as brushing the hair or lifting objects.
Other symptoms of FSHD may include hearing loss, vision problems, and foot drop. The severity of symptoms can vary widely between individuals, even within the same family.
Diagnosis of FSHD is typically based on a combination of clinical symptoms, family history, and genetic testing. There are two types of FSHD, known as FSHD type 1 and FSHD type 2. The vast majority of cases are FSHD type 1, which is caused by a genetic mutation on chromosome 4. FSHD type 2 is caused by a mutation on chromosome 18.
There is currently no cure for FSHD, and treatment is focused on managing the symptoms. Physical therapy can help maintain muscle strength and flexibility, while braces or other assistive devices can help with mobility. In some cases, surgery may be necessary to correct foot drop or other complications.
The long-term outlook for individuals with FSHD varies depending on the severity of the condition. Some individuals may have mild symptoms and a normal lifespan, while others may experience significant disability and reduced life expectancy. There is ongoing research aimed at developing new treatments for FSHD, including gene therapies and drugs that target the underlying genetic mutations.
In conclusion, Facioscapulohumeral muscular dystrophy is a genetic disorder that affects the muscles of the face, shoulders, and upper arms. It is caused by a genetic mutation that affects the expression of a protein called DUX4. Symptoms include progressive weakness and wasting of the muscles, with varying severity. Diagnosis is typically based on a combination of clinical symptoms, family history, and genetic testing. Treatment is focused on managing the symptoms, and there is ongoing research aimed at developing new treatments.