We finally investigated whether the resistant cells also had a lower incidence of mitochondrial ultrastructural abnormalities, which are characteristic of the mouse Col6a1−/− model (Irwin et al., 2003) and can also be observed in cultures established from muscle biopsies of UCMD and BM patients (Angelin et al., 2007). This evidence concerns the gene COL6A1 and Congenital muscular dystrophy, Ullrich type.