To confirm the ability of mitochondria to augment HSPCs from patients with mtDNA deletion (mtDNAdel) or mutation (mtDNAmut) syndromes, we repeated these experiments with CD34+ cells isolated from a patient with PS, a rare mitochondrial deletion syndrome, and Leigh syndrome (LS), caused in this patient by a mutation in the ND6 gene (14487 T>C). Here, MT-ND6 is linked to Leigh syndrome.