Mitochondria and Their Role in Human Reproduction.

Genetic defects of the mitochondrial genome can be especially devastating to patients; moreover, attention on human mitochondrial disorders has grown remarkably in recent years. Mitochondrial DNA (mtDNA) is maternally inherited in most eukaryotes, with paternal mtDNA being eliminated from the embryo through a variety of mechanisms. Consequently, mtDNA mutations acquired in a woman's germline can impair fertility and/or lead to severe (and even fatal) diseases in her offspring. These issues are exacerbated as the age of the mother increases. In this review, we discuss the relationship between mitochondrial dysfunction, aging, and fertility, as well as current practices for screening and diagnosing mitochondrial defects in preimplantation embryos. We also discuss recent developments in the use of mitochondrial replacement therapy to prevent the transmission of maternally-inherited mitochondrial diseases.