Assisted Reproductive Technology Treatments, Limitations And Prospects For Mitochondrial Disease Carriers Approximately 1 in 5000 to 10000 births are affected by inherited diseases caused by mitochondrial gene (mtDNA) mutations. Mitochondria are located in the cytoplasm of most cells. Metabolic characteristics are numerous and diverse dependent on cell type and activity. The central function of mitochondria and its most striking physiological role is to produce the energy of the cell, ATP (oxidative phosphorylation of ADP), through respiration, and to regulate cellular metabolism. Children and adults with mtDNA mutations have usually severe clinical symptoms and life-span may be considerably reduced. Although there may be some relief of symptoms, there is currently no cure. Women who are carriers of mtDNA mutations are at risk of transmitting mitochondrial disease to offspring. Strategies to avoid transmission include adoption and egg or embryo donation. Novel reproductive techniques designed to replace mutated mtDNA in oocytes or early embryos with those from healthy egg donors, have been proposed to prevent transmission of disease from parents to their children. One child from a cytoplasmic (ooplasmic) egg donor replacement strategy was born in 2016 in New York City. During this lecture, the efficacy and safety of mitochondrial replacement therapy (MRT) or cytoplasmic donation approaches and associated ethical and regulatory issues will be reviewed.