Abstract: Disclosed is a method for aiding in the diagnosis of merosin deficiency-type congenital muscular dystrophy (CMD). The method is based on the discovery of a previously unidentified form of CMD which is characterized by a substantial reduction in the levels of merosin in skeletal muscle tissue containing normal levels of dystrophin and dystrophin-associated proteins.

Abstract: Disclosed herein is a substantially pure nucleic acid sequence encoding a mammalian 43 kDa non-dystrophin component (.beta.-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 .beta.-sarcoglycan. Mutations in the .beta.-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 .beta.-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.