HETEROPLASMY. “Another phenomenon unique to the mitochondrial genome is the concept of heteroplasmy which arises due to the multiplicity of mtDNA copy number in each cell that can in turn give rise to a mixture of variant mtDNAs. The composition of variant mtDNAs can change over time and can differ by cell/tissue type within an individual or between individuals from the same mother, adding another dimension to mtDNA homeostasis.” Not exactly clonal inheritance.
http://onlinelibrary.wiley.com/doi/10.1002/1873-3468.12061/full