The mitochondrion (plural: mitochondria) is the organelle that generates most of the cell's supply of adenosine triphosphate (ATP) through the process of cellular respiration. The space within the inner membrane is referred to as the mitochondrial matrix. The matrix contains enzymes, mitoribosomes, and the genetic material, i.e. tRNA and DNA. DNA found within the mitochondrion is called mitochondrial DNA (mtDNA) to identify it from the DNA in the nucleus. In humans and many other species, the mtDNA is inherited solely from the mother. Nevertheless, there are certain instances that paternal inheritance of mitochondrial genome in humans was described. Mutation involving the mitochondrial DNA may lead to a disease, which is particularly referred to as a mitochondrial disease.
A mitochondrial disease is a metabolic disorder caused by mutations in mitochondrial DNA. It may be acquired or inherited. Some of the diseases being linked to dysfunctional mitochondria include DAD (diabetes mellitus and deafness), myoneurogenic gastrointestinal encephalopathy, and subacute necrotizing encephalomyelopathy.
Example of mitochondrial diseases are as follows:
- mitochondrial myopathy (e.g. Kearns-Sayre syndrome)
- Ballinger-Wallace syndrome
- Lebers hereditary optic neuropathy
- Leigh syndrome