Limb-girdle muscular dystrophies: heterogeneity of clinical phenotypes and pathogenetic mechanisms.

Limb-girdle muscular dystrophies, inherited muscle disorders characterized by progressive weakness and muscle wasting, can be classified into different types, according to their genetic inheritance, distribution of weakness, and molecular defect. The most common clinical forms are autosomal recessive and with proximal involvement, and are classified as limb-girdle muscular dystrophies 2A-2J, with clinical phenotypes ranging from severe progressive muscular dystrophy to mild late-onset forms. Advances have also been made in autosomal dominant limb-girdle dystrophies and the so-called limb-girdle muscular dystrophies 1A-1F. The recent advances in molecular pathogenetic mechanisms of limb-girdle muscular dystrophies have made an impact on the prognosis of limb-girdle muscular dystrophy patients and might be useful not only for prenatal diagnosis, in the family, but may also be of relevance for their treatment.