Fascioscapulohumeral Muscular Dystrophy

Fascioscapulohumeral Muscular Dystrophy

Asymmetric facial and scapular muscles (scapular winging) and humeral (upper arm) atrophy: difficulty whistling, closing eyes, throwing ball
Symptoms appear in adolescence
Genetics

Autosomal Dominant
D4Z4 contraction on chromosome 4q35 (Majority of genetic cause)

The following is adapted, with permission, From Robert J. Schwartzman, MD Neurologic Examination (2006) Massachusetts, USA: Blackwell Publishing.

The disease is clinically evident in the second decade of life, although up to 30% of patients may be asymptomatic.
The usual pattern of weakness is that of concomitant scapula fixator and facial weakness.
Patients cannot whistle, sip through a straw or blow out their cheeks.
Their eyes are slightly open when they sleep.
There is a descending rostral caudal weakness, facial, shoulder girdle, peroneal and hip girdle.
Patients have wide palpebral fissures, poor facial expression and a transverse smile.
Neck flexor muscles are relatively spared compared to extensors.
The shoulders are forward sloped and rounded with pectoral atrophy and axillary creases.
The scapulae are winged and laterally displaced with preferential wasting of the lower trapezius muscles.
The biceps and triceps are wasted out of proportion to the deltoids (“Popeye” appearance).
There is preferential weakness of lower abdominal muscles causing upward deviation of the umbilicus with neck flexion (Beevor's sign).
Foot dorsiflexion is involved with gastrocnemius sparing.
Reflexes are depressed.
Hearing loss and retinal telangiectasia are associated.
Approximately 5% of patients have cardiac involvement with conduction defects.
The abnormalities are primarily supraventricular tachyarrhythmias.

[Genetics Image Adapted from Images with permission from: Adapted from Mysid, based on http://ghr.nlm.nih.gov/chromosome=4 and http://www.skeletalmusclejournal.com/content/4/1/12]