Facioscapulohumeral muscular dystrophy is a heritable muscle disease, often called FSH or FSHD. (It is also known as Landouzy-Dejerine disease, after the two French neurologists who first documented it in the late 19th century). Its major effects are progressive weakening and loss of skeletal muscle. It has significant medical and health impacts on individuals, families, and society.
FSHD is amongst the most common forms of muscular dystrophy, affecting children and adults of both sexes. In the Netherlands, around 2,000 people suffer from the disease. The cardinal feature of FSHD is the progressive loss of muscle strength. The name of the disease originates from the typical pattern of weakness at onset: the face (facio), shoulder girdle (scapulo), and upper arms (humeral). However, the disease can differ in the typical initial pattern of weakness - not every patient experiences facial muscle loss, and many develop muscle weakness in the legs and torso. The symptoms can develop at any age, from infancy through to old age. Many patients recall being unable to whistle, smile, or close their eyelids as a child. The majority of males are diagnosed by age 20, and females by age 30. About 4 percent of cases are diagnosed in children under the age of 5. These early-onset or infantile-onset (iFSHD) patients are at greater risk of having more severe symptoms and added health complications. About 20% of the FSHD patients will need a wheelchair by the age of 50. At the moment there is no cure for FSHD, which is why research is so important.