This is based on: Severely affected patients with CAPN3 null-alleles, i.e. no functional calpain 3, had almost no recent regeneration and since the clinical and pathological severity of LGMD2A, LGMD2I and BMD is comparable, we can assume that it is the lack of calpain 3 in patients with LGMD2A, and not the severity of the disease, that affects the regenerative process. The gene discussed is CAPN3; the disease is autosomal recessive limb-girdle muscular dystrophy type 2I.