Facio-Scaphlo-Humeral Muscular Dystrophy (FSHD)

Facio-Scapulo-Humeral muscular dystrophy (FSHD) is a common muscular dystrophy. The name describes the usual distribution of weakened muscles: “facio”=facial; ”scapulo”=shoulder blade; “humeral”=upper arm. It is a genetic muscle disorder in which the muscles of the face, shoulder blades and upper arms are among the most severely affected. However, the legs may also be affected.

Features

• The presenting weakness can vary widely between different affected members in a family.
• For some affected individuals, there is only mild weakness of facial muscles whereby the eyes remain slightly open when asleep, or the eyelids cannot be screwed tightly to bury the eyelashes. There may be difficulties in pursing the lips to whistle or to play a woodwind or brass instrument, or in blowing up balloons.
• During the teenage years or in adulthood, excessive aching around the shoulders and thin upper arms may be the first presenting signs or symptoms.
• For other affected individuals, weakness is not only restricted to the facial and shoulder/upper arm muscles, but also involves the neck, forearms, wrists, fingers, hips, legs, ankles and the back muscles. Around 10-20% of affected individuals eventually require a wheelchair.
• Generally speaking, lifespan is not affected, except perhaps in the most severe cases with greatly impaired mobility and greater risk of chest infections. There are some recent reports suggesting an increased association with heart rhythm disorders.

Cause

FSHD is caused by genetic faults involving the long (q) arm of chromosome 4.