Homoplasmy

Homoplasmy is the presence of a mutation affecting all of the mitochondrial DNA (mtDNA) copies in a cell. Since there are hundreds or even thousands of mtDNA copies in every eukaryotic cell, mutations may either be present in all copies (homoplasmy) or affect only a fraction of them (heteroplasmy).

See also microheteroplasmy.

Homeoplasmy = a state in which all the mitochondria of a cell or a tissue have the same genome, which may be either the wild type genome or a mutated one.