[Updates in muscular dystrophies]

Abstract

Introduction: Advances in molecular genetics on lasts 15 years had modified profoundly our knowledge about muscular dystrophies. The pathogenia, caused by defectives proteins which disrupt dystrophin-associated-protein complex in most of the dystrophies, has generate a new classification based in protein and genomic defects.

Development: In this review, clinical, genetic, diagnostic and therapeutic aspects of the main muscular dystrophies are described. Limb girdle muscular dystrophies with Duchenne-like phenotype (sarcoglycanopathies), are identified by immunohistochemistry, as X-linked Emery-Dreifuss muscular dystrophy (emerin deficit), and classical congenital muscular dystrophy (merosine depletion). The others limb girdle muscular dystrophies, an heterogeneous phenotypical group, are detected by Western blot (mainly calpainopathies), or inmunohistochemistry in muscle (caveolinopathies) and blood (dysferlinopathies). Congenital muscular dystrophies with brain malformations: Fukuyama, muscle-eye-brain, and Walker-Warburg syndrome; and fukutin-related protein dystrophy, only may be differentiated by genetic analysis. All them shows alpha-dystroglican depletion. Autosomal dominant Emery-Dreifuss muscular dystrophy and facioscapulohumeral dystrophy are exclusively identified by DNA study. Finally, Duchenne/Becker muscular dystrophies are diagnosed by immunohistochemistry, Western blot and/or DNA analysis. Treatment of muscular dystrophies is based in physiotherapy, ventilatory support, surgery and drugs (mainly steroids, effective in Duchenne/Becker muscular dystrophies).

Conclusion: Genic and cellular therapy are yet on experimental field, and are matter of the future. Now, accurate diagnosis is important for therapeutic management, prognosis and genetic counseling.