ADVANCES IN THE MOLECULAR-GENETICS OF THE LIMB-GIRDLE TYPE OF AUTOSOMAL RECESSIVE PROGRESSIVE MUSCULAR-DYSTROPHY

A reclassification of the limb-girdle types of autosomal recessive mus cular dystrophy based on genetic and protein information has been made possible by major advances over the past 2 years. At least six differ ent forms of limb-girdle types of autosomal recessive muscular dystrop hy can be defined by their genetic basis, with at least two pathogenic mechanisms involved. Three forms are defined by involvement of differ ent proteins of the sarcoglycan complex, while a muscle specific prote ase (calpain 3) is implicated in another form of the recessive disease . These findings provide the basis for a new diagnostic approach to th e group, with molecular techniques now an essential part of the diagno stic process, A scheme for diagnosis in this group is proposed.