A targeting vector was designed to introduce an H77C (TGC->CAC) missense substitution in exon 3, and place a loxP-flanked pgk-neomycin resistance cassette (in opposite transcriptional orientation) into intron 3 of the gene. Alpha-sarcoglycan mRNA is not detected by RT-PCR, and protein is not detected by Western blot or immunofluorescence staining of skeletal muscle. (J:130252)