Emerging therapeutic strategies for mitochondrial DNA-related diseases.

Primary mitochondrial diseases (PMDs) are among the most common inherited metabolic disorders, affecting approximately 1 in 4,300 individuals. They result from pathogenic variants in mitochondrial DNA (mtDNA) or nuclear DNA (nDNA) that disrupt oxidative phosphorylation and lead to multisystem disease. Although advances in genomic testing have significantly improved diagnostic rates in PMDs, effective disease-modifying therapies remain limited. Therapeutic development increasingly focuses on mtDNA-targeted approaches because mtDNA variants are a major cause of disease and may offer opportunities for targeted intervention. Current strategies include allotopic expression, mitochondria-targeted nucleases, and next-generation base editors, which reduce or correct pathogenic mtDNA variants. Other emerging approaches include pharmacological modulation of heteroplasmy, reproductive techniques such as mitochondrial donation, and therapeutic strategies based on mitochondrial transplantation. This review summarizes advances in gene editing, pharmacological approaches, and reproductive and mitochondrial transplantation strategies for mtDNA-related PMDs, highlighting progress toward more targeted interventions.