mRNA expression levels of TSP genes in human primary myoblasts isolated from DMD donors. Bar graphs showing the CBS, CSE, 3-MST, CDO, CSAD, γ-GCS and GS mRNA expression levels in primary human myoblasts isolated from two healthy (HD1 and HD2) and four DMD donors (D1–D4). The quantification of transcripts has been performed in duplicate for each donor as indicated by the single dots shown on the graph. The difference in the expression levels of TSP genes are calculated by combining healthy and/or DMD donors together. Each bar is, therefore, the mean ± SEM of two healthy vs four DMD donors. *p ≤ 0.05 and **p ≤ 0.01 vs healthy donors.