Cell culture
Myoblasts were isolated from the biopsied tissue by muscle explants and then purified by CD56 magnetic separation. Early passage myoblasts were grown until 60-70% confluent on 0.1% gelatin-coated flasks in proliferation medium containing DMEM supplemented with 10% FBS, 22% M-199, PSF 1x, insulin 1.74 μM, L-glutamine 2 mM, FGF 1.39 nM and EGF 0.135 mM. Cells for DNA extraction and FISH staining were obtained between passages P2 and P6.