CAPN3 and limb-girdle muscular dystrophy: However, Vissing and colleagues reported 37 patients from 10 European families with an autosomal dominant LGMD co-segregating with an in-frame 21-bp deletion (c.643_663del21, p. Ser215_Gly221del) in CAPN3. 3Nine affected patients had a milder phenotype than those affected by LGMDR1, with normal expression of the mutated mRNA and no evidence of nonsense-mediated mRNA decay, but there was a significant decrease (<15% of control values) at protein levels measured by Western blot analysis.