Haplogroup K1a1b1a (mtDNA)

In human mitochondrial genetics, Haplogroup K1a1b1a is a human mitochondrial DNA (mtDNA) haplogroup.

The K1a1b1a mitochondrial DNA haplogroup subclade is found in Ashkenazi Jews and other populations. It is a subclade under haplogroup U'K.

Origin

According to National Geographic's Genographic Project, K1a1b1a has an unknown origin. The site stated, "Though the origin of this lineage is not clear, it is a founding population among some Jewish Diaspora groups. Among Ashkenazi Jews, it is about 19 percent of maternal lineages." Estimates of the age of K1a1b1a vary depending on the mutation rates used. The age of K1a1b1a has been estimated at 4,800 ± 3,600 Years Ago, according to the Genographic Project.

The K1a1b1a subclade is under the U'K haplogroup and descends from K1a1b1, which is thought to be an 11,500-year-old European subclade of mostly non Jewish origins. Haplogroup K falls under the old U8 grouping. Some of the Basque people of Spain and France fall under the U8a subclade within U8. K1a1b1a is a U8b subclade within U8, with several downstream variations.

Ötzi, a mummy who was found September 1991 in the Ötztal Alps, is subclade K1ö. Ötzi has mtDNA marker 10978 in common with the Ashkenazi population and others who fall under the K1a1b1a subclade.

By the time of Build 17, released on February 18, 2016, van Oven's phylogenetic tree, called the PhyloTree, updated its definition of K1a1b1a. Now, it requires the presence of the markers 10978 and 12954 in the coding region, and 16234 in the first hypervariable region (HVR1). The mutations involved are written out as A10978G (meaning A transitioned to G), T12954C (meaning T transitioned to C), and C16234T (meaning C transitioned to T). The definition of K1a1b1a no longer requires the mutation (C114T) on the highly polymorphic marker 114 in the second hypervariable region (HVR2). In Build 3, K1a1b1a had been defined by (114), 10978, and 16234 but did not need 12954. In Build 17, (C114T) appears as part of the definition of K1a1 instead. A minority of K1a1b1a carriers, such as JQ702155 and JQ703012, are missing (C114T).

Distribution

10% of Europeans fall under the K haplogroup. It is hypothesized that the subclade represents one of four major founding maternal lineages ("founding mothers") of Ashkenazi Jews which together account for 45% of all Ashkenazi mtDNA haplotypes. Approximately 19% of Ashkenazi Jews with ancestry from Poland are in mtDNA haplogroup K1a1b1a. However, K1a1b1a has also been found in individuals of no known Jewish ancestry, and the explanation will require further research. The Genographic Project along with other research groups are looking into this phenomenon. The haplogroup is distributed in Europe and the Middle East. Estimates suggest approximately 1,600,000 Jews worldwide would be K1a1b1a.

The field of genetic genealogy and DNA sequencing has permitted ordinary people to make use of DNA testing to establish some evidence for their ancestral origins. Thousands of Family Tree DNA customers have submitted their mtDNA sequences for use in scientific studies, including those led by Behar and Brook. Additional samples were provided by the National Laboratory for the Genetics of Israeli Populations. Accordingly, based on the research of Behar, some connection has been established between the K1a1b1a subclade and Jewish ancestry. Aside from Ashkenazi Jews, K1a1b1a is also found in multiple communities of Sephardic Jews from Italy, Turkey, and southeastern Europe along with Baghdadi Jews from India and Paradesi Jews from India. It is also present among the Xueta people of Spain. The notion of Romani origins for K1a1b1a is impossible, given the much greater genetic diversity of K1a1b1a in Jews and the fact that this haplogroup was already widespread in Jewish populations by the 14th century. The presence of K1a1b1a in Romani people in Poland is the result of introgression into a Romani population.

A growing number of GenBank samples support the observations of mutations and population distributions described above.

It may be recognized in hypervariable-only samples by the following essential mutations:

• Hypervariable region 1: 16224C, 16234T, 16311C, 16519C
• Hypervariable region 2: 073G, 263G, 315.1C, 497T

Pre-Modern K1a1b1a Samples

Notable individuals with Haplogroup K1a1b1a

• Singer and pianist Harry Connick Jr.
• Actress and singer Tovah Feldshuh
• Novelist and journalist Keith A. Gessen
• Broadcaster and journalist Ramona Koval
• Futurist Donald Prell

Subclades

Tree

This phylogenetic tree of haplogroup K subclades is based on the paper by Mannis van Oven and Manfred Kayser Updated comprehensive phylogenetic tree of global human mitochondrial DNA variation and subsequent published research.

• K1a1b1 11470G
  • K1a1b1a 10978G 12954C 16234T
  • K1a1b1b 593C 2483C
    • K1a1b1b1 789C 11620G
  • K1a1b1c 5585A 16222T
  • K1a1b1d 14388G 16092C 16223T
  • K1a1b1e 9932A
  • K1a1b1f 4823C 6528T 8842C
  • K1a1b1g 5583T 12007A

See also

• Genealogical DNA test
• Genetic Genealogy
• Human mitochondrial genetics
• Population Genetics
• Human mitochondrial DNA haplogroups

References

External links

• Websites
  • Mannis van Oven's PhyloTree [1]
  • Ian Logan's Mitochondrial DNA Site's K1a1b1 Page
  • YFull's K1a1b1a MTree
  • mtDNA Haplogroup K Project at Family Tree DNA
  • The Genographic Project by National Geographic

1. Haplogroup K (mtDNA)
2. List of haplogroups of historic people
3. Genetic studies of Jews