Muscular dystrophy, facioscapulohumeral

A genetic muscle disorder affecting the face, shoulder blades, and upper arms

Facioscapulohumeral muscular dystrophy
Synonyms	FSHD
Pronounce	N/A
Specialty	N/A
Symptoms	N/A
Complications	N/A
Onset	Usually in adolescence or early adulthood
Duration	Lifelong
Types	N/A
Causes	Genetic mutation
Risks	N/A
Diagnosis	Genetic testing, clinical evaluation
Differential diagnosis	N/A
Prevention	N/A
Treatment	Physical therapy, orthopedic interventions
Medication	N/A
Prognosis	N/A
Frequency	1 in 20,000
Deaths	N/A

Facioscapulohumeral muscular dystrophy (FSHD) is a genetic muscle disorder characterized by progressive skeletal muscle weakness, primarily affecting the muscles of the face (facio), shoulder blades (scapulo), and upper arms (humeral). It is one of the most common forms of muscular dystrophy.

Genetics

FSHD is typically inherited in an autosomal dominant pattern, meaning a single copy of the mutated gene can cause the disorder. The most common genetic cause of FSHD is a contraction of the D4Z4 repeat on chromosome 4q35. This contraction leads to the inappropriate expression of the DUX4 gene, which is toxic to muscle cells.

Symptoms

The symptoms of FSHD can vary widely among individuals, even within the same family. Common symptoms include:

• Weakness of the facial muscles, leading to difficulty with facial expressions.
• Scapular winging due to weakness of the shoulder girdle muscles.
• Weakness of the upper arm muscles, which can affect the ability to lift objects.
• As the disease progresses, weakness may also affect the abdominal muscles and lower limbs.

Diagnosis

Diagnosis of FSHD is based on clinical evaluation, family history, and genetic testing. Genetic testing can confirm the diagnosis by identifying the characteristic D4Z4 contraction on chromosome 4q35.

Management

There is currently no cure for FSHD, but management focuses on alleviating symptoms and improving quality of life. This may include:

• Physical therapy to maintain muscle strength and flexibility.
• Orthopedic interventions, such as braces or surgery, to address skeletal deformities.
• Pain management strategies.

Prognosis

The progression of FSHD is highly variable. Some individuals may experience mild symptoms and maintain a normal lifespan, while others may develop significant disability. Respiratory involvement is rare but can occur in severe cases.

Research

Ongoing research is focused on understanding the molecular mechanisms of FSHD and developing targeted therapies. Gene therapy and other molecular approaches are being explored as potential treatments.

Also see

• Muscular dystrophy
• Genetic disorders
• Physical therapy
• Orthopedic surgery