Screening for genetic defects in the cells should be examined for clinical application. The
Pearson syndrome (PS) patient harbored nuclear mutations in the POLG and SSBP1 genes, which could induce systemic large-scale mitochondrial genome (
mtDNA) deletion. We investigated iPSCs with
mtDNA deletions in PS patient and whether deletion levels could be maintained during differentiation. The iPSC clones derived from skin fibroblasts (9% deletion) and blood mononuclear cells (24% deletion) were measured for
mtDNA deletion levels. Of the 13 skin-derived iPSC clones, only 3 were found to be free of
mtDNA deletions, whereas all blood-derived iPSC clones were found to be free of deletions. The iPSC clones with (27%) and without
mtDNA deletion (0%) were selected and performed in vitro and in vivo differentiation, such as embryonic body (EB) and
teratoma formation. After differentiation, the level of deletion was retained or increased in EBs (24%) or
teratoma (45%) from deletion iPSC clone, while, the absence of deletions showed in all EBs and
teratomas from deletion-free iPSC clones. These results demonstrated that non-deletion in iPSCs was maintained during in vitro and in vivo differentiation, even in the presence of nuclear mutations, suggesting that deletion-free iPSC clones could be candidates for autologous
cell therapy in patients. [BMB Reports 2023; 56(8): 463-468].