Inheritance: autosomal dominant, so other family members may be affected
Chromosome affected: 4q35
Clinical features:
(1) Weakness of facial muscles occurs early.
(2) "Scapular winging" (caused by weakness in the scapular stabilizers) occurs early.
(3) Hip-girdle and distal leg weakness occur later.
(4) There is often sparing of the deltoid muscles.
(5) The patient may develop mild scoliosis.
(6) Variable findings include pectus excavatum, retinal vasculopathy, and high-frequency sensorineural hearing loss.
(7) The disorder is usually slowly progressive
(8) Some patients may become unable to walk and will require use of a wheelchair.
The changes on the EMG may be nonspecific.
The serum CK may be elevated.
Histologic findings on a muscle biopsy may range from almost normal to myopathic changes with an inflammatory infiltrate.
The differential diagnosis of scapular winging includes accessory nerve palsy and serratus anterior nerve palsy.
