G-I When myoblasts started to be confluent, the proliferation medium was replaced with differentiation medium, and the myoblasts started to fuse yielding myotubes, which were analyzed after four days of differentiation. (H) The fusion index, which measures the percentage of nuclei in myotubes with respect to the total number of nuclei in myogenic cells, was higher in D233E cultures than in controls. (I) Besides, myogenin showed increased expression in D233E myoblast cultures compared to controls. The data support that differentiation process is facilitated in patient´s muscle. Data was collected from 3-10 randomly chosen areas per condition (mean ± SEM is shown; Kruskal-Wallis with Dunn´s multiple comparisons test (H) and One-way Anova with Bonferroni´s multiple comparisons test (I); Scale bar, 50 µm). 