mtDNA
Human mitochondrial DNA (mtDNA) is a nonrecombining genome that codes for 13 subunits of the mitochondrial oxidative phosphorylation system, 2 rRNAs and 22 tRNAs. Mutations have accumulated sequentially in mtDNA lineages that have diverged tens of thousands of years ago. The genes in mtDNA are subject to different functional constraints and are therefore expected to evolve at different rates, but the rank order of these rates should be the same in all lineages of a phylogeny.
Single deletions of mitochondrial DNA (mtDNA) are associated with three major clinical conditions:
- Kearns-Sayre syndrome, a multisystem disorder
- Pearson syndrome, a disorder of the hematopoietic system
- progressive external ophthalmoplegia, primarily affecting the ocular muscles.
References
Carelli V, Giordano C, d'Amati G. Pathogenic expression of homoplasmic mtDNA mutations needs a complex nuclear-mitochondrial interaction. Trends Genet. 2003 May;19(5):257-62. PMID: #12711217#
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