People with mitochondrial disease carry a mutation in a gene that affects the way their mitochondria work. Mitochondrial inheritance can be complex.
People with mitochondrial disease carry a mutation in a gene that affects the way their mitochondria work.
Mitochondria are complex structures within our cells. Their job is to produce energy for the cells to function. They do this with proteins coded by DNA both within the mitochondria and in the nucleus, at the center of a cell. These two types of DNA are called mitochondrial DNA or mtDNA and nuclear DNA. Both are needed for the mitochondria to function normally.
Inheritance of mitochondrial disease can be complex. It can be caused by mutations in the main nuclear DNA, or by mutations in the mtDNA. Mitochondrial disease can be due to any type of inheritance pattern, including mitochondrial inheritance.
Mitochondrial inheritance refers to inheritance of those genes that are located in the mtDNA. Individuals with mtDNA mutations may be male or female, but only women pass on mtDNA — and its mutations — to their children. Remember, women have no control over what is passed on.
Even more complex is that all of a woman’s mitochondria may not carry a mtDNA mutation. Therefore, not all children of a woman who carries a mtDNA mutation will inherit the mutation and develop the condition, or at least, not to the same degree.*