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Chromosome browser

From ISOGG Wiki

A chromosome browser is a tool that provides a visual representation of one or more chromosomes.

Autosomal DNA

In autosomal DNA testing the term chromosome browser is used to describe a tool which allows the user to do a comparison between one or more matches to see how much DNA the user shares shared in common with them. The browser provides a graphical view of the half-identical segments shared with the match or matches on each individual chromosome. Matches can be on the paternal or maternal chromosome but the chromosome browser cannot distinguish between the two.

Some chromosome browsers allow the user to view fully identical regions – segments of the chromosome which are identical on both the maternal and paternal chromosome.

A chromosome browser is currently provided with Family Tree DNA's Family Finder test and with the DNA Relatives feature of the 23andMe test. The 23andMe chromosome browser is known as the Family Inheritance: Advanced tool. 23andMe also provides a chromosome browser with its Genome-Wide Comparison facility. This tool can be found under Family and Friends/Family Traits. The Genome-Wide Comparison also allows users to see if they share any fully identical regions with their matches. 23andMe's US customers were moved over to the new 23andMe in 2016. In the new version of DNA Relatives the chromosome browser is known as the DNA View. The DNA View does not currently allow users to see fully identical regions.

Examples of comparisons using the Family Tree DNA chromosome browser can be seen in the article on chromosome browser examples.

A chromosome browser is also provided by the free third-party websites GedMatch and DNA.Land. The GedMatch browser also has the facility to view fully identical regions.

Further reading

Y-chromosome DNA

ISOGG has a human Y-chromosome browser known as YBrowse which can be used to examine SNPs in different regions of the Y-chromosome. YBrowse is based on Human Genome Version 38 (hg38; Genome Reference Consortium GRCh38). The browser is maintained by Thomas Krahn.

It is also possible to explore Y-chromosome next generation sequencing data by using one of the many available genome browsers. See the Wikipedia article on genome browsers for an extensive list.

See also