9bp deletion
From ISOGG Wiki
The nine base pair deletion (9bp deletion) is a common mutation seen in mitochondrial DNA sequences. It occurs in the coding region between positions 8281 and 8289. The sequence will appear in the mutation list as:
- 8281- 8282- 8283- 8284- 8285- 8286- 8287- 8288- 8289- (rCRS - revised Cambridge Reference Sequence)
- 8281d 8282d 8283d 8284d 8285d 8286d 8287d 8288d 8289d (RSRS - Reconstructed Sapiens Reference Sequence).
At this region in the mtDNA genome there is a nine base pair sequence that repeats two or three times. It's like a very short, but giant STR, and it has a tendency to mutate in repeats rather than in a single position. Sometimes the mtDNA loses a repeat (the 9bp deletion) and sometimes the mtDNA adds a repeat (9bp insertion). The deletion is seen in nearly all of haplogroup B and it also occurs at random in other haplogroups.[1] Three examples of the 9bp deletion have been found in the mtDNA haplogroup U4 project as of January 2015.[2]
The deletion should be treated as a single mutation but is not currently treated as such by the Family Tree DNA mtDNA matching algorithms.
References
Blog posts
- Whittall A. The recurrent 9-bp deletion in mtDNA. Patagonian Monsters blog, 24 July 2014.
- Dziebel G. The origin of mtdna haplogroup B: 9-bp deletion in America, Asia and Africa. Anthropogenesis blog, 21 March 2012.
Scientific papers
- Thomas MG, Cook CE, Miller KWP (1998). Molecular instability in the COII±tRNALys intergenic region of the human mitochondrial genome: multiple origins of the 9-bp deletion and heteroplasmy for expanded repeats. Philosophical Transactions of the Royal Society London B 353: 955-965.