inheritance, mitochondrial

inheritance, mitochondrial The inheritance of a trait encoded in the mitochondrial genome. Mitochondrial inheritance does not obey the classic rules of genetics. Mitochondrial DNA is always inherited from the mother only, meaning that persons with a mitochondrial disease may be male or female but are always related in the maternal line, and no male with the disease can transmit it to his children. The mitochondria are structures in the cell’s cytoplasm, located outside the nucleus, and are responsible for energy production (metabolism). See also mitochondria; mitochondrial diseases.