pediatrics
Facioscapulohumeral Muscular Dystrophy
Introduction
Facioscapulohumeral muscular dystrophy is the third most prevalent type of muscular dystrophy. Most cases manifest by age 20. It is characterized by weakness of the facial muscles and shoulder girdle. The course is variable. Diagnosis is by DNA analysis. Treatment is symptomatic, usually with physical therapy. Muscular dystrophies are inherited, progressive muscle disorders resulting from defects in one or more genes needed for normal muscle structure and function; dystrophic changes (eg, muscle fiber necrosis and regeneration) are seen on biopsy specimens. Facioscapulohumeral muscular dystrophy (FSHMD) is the third most prevalent type of muscular dystrophy (after Duchenne and Becker muscular dystrophies and myotonic dystrophy) and occurs in 4 to 12/100,000 ( General reference ) people. FSHMD is an Autosomal Dominant disorder. In about 98% of patients, it is caused by a deletion on the long arm of chromosome 4, at the 4q35 locus. In up to 30% of patients, the mutation is de novo (sporadic) rather than inherited. 