The article reviews the advances and challenges in understanding mitochondrial DNA (mtDNA) mutations and their impact on human disease. MtDNA, despite its small size, plays a crucial role in various genetic disorders and is central to evolutionary genetics and forensic medicine. Recent progress has been made in identifying mtDNA mutations associated with diseases such as Kearns–Sayre syndrome, Leber Hereditary Optic Neuropathy (LHON), and Leigh syndrome. However, many challenges remain, including the prevention and treatment of these diseases. The review highlights the importance of understanding the basic processes of mtDNA replication, transcription, and translation, as well as the clinical syndromes caused by mtDNA mutations. It also discusses the management of mtDNA diseases, the potential for gene-based treatments, and the role of mtDNA in ageing and cancer. The authors emphasize the need for further research to improve diagnosis, treatment, and prevention of mtDNA-related disorders.The article reviews the advances and challenges in understanding mitochondrial DNA (mtDNA) mutations and their impact on human disease. MtDNA, despite its small size, plays a crucial role in various genetic disorders and is central to evolutionary genetics and forensic medicine. Recent progress has been made in identifying mtDNA mutations associated with diseases such as Kearns–Sayre syndrome, Leber Hereditary Optic Neuropathy (LHON), and Leigh syndrome. However, many challenges remain, including the prevention and treatment of these diseases. The review highlights the importance of understanding the basic processes of mtDNA replication, transcription, and translation, as well as the clinical syndromes caused by mtDNA mutations. It also discusses the management of mtDNA diseases, the potential for gene-based treatments, and the role of mtDNA in ageing and cancer. The authors emphasize the need for further research to improve diagnosis, treatment, and prevention of mtDNA-related disorders.