β-sarcoglycan nucleic acid sequence, and nucleic acid probes

Disclosed herein is a substantially pure nucleic acid sequence encoding a mammalian 43 kDa non-dystrophin component (β-sarcoglycan) of the dystrophin-glycoprotein complex. Also disclosed are immunogenic peptides which, when used to immunize a mammal, stimulate the production of antibodies which bind specifically to the β-sarcoglycan. Mutations in the β-sarcoglycan gene which are associated with autosomal recessive limb-girdle muscular dystrophy are also disclosed. The identification of such mutations enables the design of nucleic acid probes which hybridize specifically to a mutant form of β-sarcoglycan, or the complement thereof, but not to the DNA of the wild-type form of the gene (or the complement thereof), under stringent hybridization conditions. Such probes are useful, for example, in connection with the diagnosis of autosomal recessive limb-girdle muscular dystrophy. In addition, the identification of such mutations enables the diagnosis of autosomal recessive limb-girdle muscular dystrophy through the use of direct DNA sequencing techniques.