What is the Cambridge Reference Sequence (CRS)?
It is the DNA sequence of the first human mitochondrial genome to be completely determined. The nucleotides of this standard molecule are numbered from 1 to 16569. Published in 1981, the sequence was recently revised to correct minor errors in the initial sequence. Each mtDNA haplotype is described by the differences it shows with the rCRS. The history of the sequence changes is described in the Mitomap website. It is important to note that this is not in any way a special mitochondrial sequence – any human mitochondrial genome could be used as a reference. There has to be some standard sequence though, so that mitochondrial genomes can be aligned and compared.
• This is the mitochondrial DNA (mtDNA) sequence against which we compare all of the mtDNA sequences generated for our customers. It was determined by a group of researchers in Cambridge (hence the name) as being the most common sequence found in native Europeans. If your sequence is the same as the CRS, then you are in the clan of Helena.
The CRS is the Cambridge Reference Sequence. It was the first mtDNA sequence to be completed, and all mtDNA tests are now compared to a revised edition of it. • What are haplogroups? Haplogroups are genetic population groups. Mitochondrial haplogroups are composed of people who share a common ancestor on their direct maternal lineage. Your haplogroup tells you what branch on the mitochondrial tree of humanity you belong to. • What is my haplogroup? You will find your haplogroup assignment in the mtDNA Results section of your myFTDNA site. If you took the mtDNA or the mtDNA Plus test then your haplogroup was determined using a panel of twenty-two Single Nucleotide Polymorphisms, SNPs. If you took the mtDNA Full Genomic Sequence, FGS, test then it was determined with your full results. • What are supergroups? Supergroups or macro-haplogroups are the foundation for a number of other haplogroups. They represent older shared ancestors on the maternal tree. They link together many of the mor
