23andMe Updated Paternal Haplogroup Assignments

23andMe has updated their haplogroup tree. The changes reflect the work of the International Genealogy Society of Genetic Genealogy. 23andMe is introducing yHaplo, their new open-source software for researchers.

A haplogroup is a genetic population group of people who share a common ancestor on the patrilineal or matrilineal line. Haplogroups are assigned letters of the alphabet, and refinements consist of additional number and letter combinations.

23andMe points out that fathers pass down copies of their Y-chromosomes to their sons. Small variations arise over time and accumulate in patterns that uniquely mark individual paternal lineages. From this, scientists were able to build a “tree” that showed how global Y-chromosomes related to one another.

Recent research from a study published in Nature Genetics drastically redefined the structure of the tree. An international team of 42 scientists used complete Y-chromosome sequences from around the world to carry out the largest-ever study of genetic variation within the human Y-chromosome. This research identified more than 65,000 Y-chromosome genetic variants.

Male customers on the new 23andMe website experience can expect to see changes to their paternal haplogroup assignment. Female customers may see changes to the paternal haplogroup assignments of male relatives and friends in other parts of the website.

Another update is to the naming system that 23andMe used to report paternal haplogroups. Previously, the naming system involved a lengthy series of letters and numbers (that related to the path of branches of the most recent common ancestor of all men to each haplogroup). This led to confusion.

From now on, each name will use a letter to identify the major branch of the tree and the name of a genetic marker unique to a specific haplogroup. This new representation focuses on a specific informative marker associated with your haplogroup and it will be much more stable over time than the previous naming pattern was.

23andMe has introduced yHaplo. It is a new open-source research tool. In short, it includes an algorithm developed by David Poznik (23andMe population geneticist and Y-chromosome expert). The yHaplo software is flexible and runs on full Y-chromosome sequences and on small sets of genotyped markers.

The software will be used by 23andMe to provide haplogroup assignments to their customers. The yHaplo software is also being provided to researchers under a custom open-source software license for non-commercial use.

Related Articles at FamilyTree.com:

* 23andMe Launched New Genotyping Services for Research

* 23andMe Resumes Genetic Testing

* FDA Approves 23andMe’s Test for Bloom Syndrome

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