Hereditary myopathies are inherited disorders primarily affecting the skeletal muscle tissue. These are caused by mutations in different genes-encoding proteins that play important roles in muscle structure and function. Skeletal muscle weakness and hypotonia are typical clinical manifestations in most of hereditary myopathies. Histological features such as fiber type disproportion, myofibrillar disorganization, and structural abnormalities are usually observed in muscle biopsies of non-dystrophic myopathies, while fibrosis, fiber regeneration, wasting, and atrophy are characteristic of dystrophic myopathies. However, similar histopathological features may overlap in different hereditary myopathies. This is how mutations in a same gene can lead to different forms of hereditary myopathies and a same myopathic phenotype can derive from defects in different related genes making difficult a specific diagnosis. In this regard, understanding all aspects of hereditary myopathies can facilitate a better diagnosis and treatment. In this chapter, we offer a review of some of the most prevalent hereditary myopathies, highlighting clinical, histological, and molecular aspects of these muscle disorders.
Part of the book: Muscle Cell and Tissue