(B) mtDNA NGS showing the position and mutation load of GPMs in seven isogenic MitoA-derived hiPSCs clones and their differentiated counterparts. The mtDNA genotype is stable during in vitro cardiac differentiation and lactate enrichment. MitoA hiPSCs 57 and 65 (wild-type) are labelled in black, MitoA hiPSCs 61 and 69 (m.3243A>G mutant) are labelled in red and MitoA hiPSCs 58, 59 and 217 (with amplified GPMs in nuclear reprogramming) are labelled in blue. 