Fascioscapulohumeral dystrophies
Objectives- Describe presenting symptoms and natural history
of fascioscapulohumeral dystrophy
- Describe the genetic transmission of fascioscapulohumeral
dystrophy
- Discuss useful orthopaedic intervention for fascioscapulohumeral
dystrophy
Fascioscapulohumeral dystrophy (FSHD) is an unusual form of muscular dystrophy which was one of the types described by Walton and Nattrass in their classic 1954 work on the muscular dystrophies. It is transmitted as an autosomal dominant with significantly higher penetrance in males than in females. The genetic defect was located in 1990 located on chromosome 4, and it has been documented that in normal individuals, genetic probing detects an EcoRI fragment > 35 Kb, while in FSHD families, a shorter fragment, usually between 14-35 Kb is found. SFSHD affects the facial and shoulder girdle musculature in a highly variable fashion, both in age of onset and severity of disease. The deltoid is spared. Some individuals with the condition can only be detected with careful exam techniques, while about 10% become wheelchair bound. About 85% are affected by age 20. In a recent study, the penetrance was 95% for males and 69% for females.
The major orthopaedic problem with FSHD is weakness of shoulder abduction and flexion. Posterior scapulothoracic fusion stabilizes the scapula, and affords better mechanical advantage to the unaffected rotator cuff and deltoid.
References
- Emery AE. The muscular dystrophies. Bmj 1998; 317( 7164): 991-5.
- Thompson GH. Neuromuscular disorders. In: Morrissy RT, Weinstein SL, editors. Pediatric Orthopaedics. Philadelphia: Lippincott-Raven Press; 1996. p. 537-77.
- 3. Twyman RS, Harper GD, Edgar MA. Thoracoscapular fusion in facioscapulohumeral dystrophy: clinical review of a new surgical method. Journal of Shoulder & Elbow Surgery 1996; 5( 3): 201-5.
- Walton JF, Nattrass FJ. On the classification, natural history, and treatment of the myopathies. Brain 1954; 77: 169-231.
- Zatz M, Marie SK, Cerqueira A, Vainzof M, Pavanello RC, Passos-Bueno MR. The facioscapulohumeral muscular dystrophy (FSHD1) gene affects males more severely and more frequently than females. American Journal of Medical Genetics 1998; 77( 2): 155-61.
May 16-19, 2012 in Denver, CO
