'Heteroplasmy' is the presence of a mixture of more than one type of an
organellar genome (
mitochondrial DNA (mtDNA) or
plastid DNA) within a cell or individual. Since every
eukaryotic cell contains many hundreds of mitochondria with hundreds of copies of mtDNA, it is possible and indeed very frequent for
mutations to affect only some of the copies, while the remaining ones are unaffected.
See also
★
homoplasmy
★
microheteroplasmy
★
Paternal mtDNA transmission