Limb-girdle muscular dystrophy: one gene with different phenotypes, one phenotype with different genes

Among 14 limb-girdle muscular dystrophy genes that have been mapped, 10 (th ree autosomal dominant and seven autosomal recessive) have so far had their product identified. This review will focus on the most recent data in the field and on our own experience of more than 200 patients studied with auto somal recessive-limb-girdle muscular dystrophy, classified from calpainopat hy to telethoninopathy. Genotype:phenotype correlations in this highly hete rogeneous group show a similar clinical course among patients with differen t forms, whereas a discordant phenotype may be seen in unrelated patients o r in affected sibs carrying the same mutation. Understanding such similarit ies or differences remains a major challenge. It will depend on future know ledge of gene-protein functions, on protein interactions and on identifying modifying genes and other factors underlying clinical variability. Curr Op in Neurol 13:511-517. (C) 2000 Lippincott Williams & Wilkins.