mitochondrial D-loop poly-cytidine repeat
Somatic mutations at a mitochondrial noncoding polycytidine (C)(n) repeat (polyC) have been associated with tumor progression.
The increased mutability of repeated mitochondrial sequences is dependent on the repetitive structure of the DNA molecule.
Mutations in the (C)(n) repeat, whether homoplasmic or not, and by extrapolation, mitochondrial mutations in general, could not be the result of selective pressure during tumorigenesis. (#16708351#)
The (C)(n) repeat may be used as an universal molecular clock to estimate the relative mitotic history of tumors. (#16708351#)
References
Schwartz S Jr, Alazzouzi H, Perucho M. Mutational dynamics in human tumors confirm the neutral intrinsic instability of the mitochondrial D-loop poly-cytidine repeat. Genes Chromosomes Cancer. 2006 Aug;45(8):770-80. PMID: #16708351#