Facioscapulohumeral muscular dystrophy (FSHD) is a genetic disorder caused by a deletion of a portion of chromosome 4. This deletion causes a disruption in the expression of a gene called DUX4, resulting in progressive muscle weakness, mainly affecting the face, shoulder blades, and upper arms.
Diagnosis of FSHD is typically made through a combination of physical exam, family history, and genetic testing. Physical exam findings may include weakened facial muscles, shoulder girdle weakness, and scapular winging, and genetic testing can confirm the diagnosis by identifying a deletion on chromosome 4.
Differential diagnosis includes other forms of muscular dystrophy, such as Becker muscular dystrophy and limb-girdle muscular dystrophy.
Treatment of FSHD is mainly supportive and includes physical therapy, occupational therapy, and bracing to help manage symptoms. Drugs such as corticosteroids may also be used to help reduce symptoms.
Prognosis of FSHD is variable and depends on how much muscle has been affected and how aggressive the disease is. In most cases, symptoms can be managed, but in severe cases, the disorder may lead to severe disability.