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X-chromosome testing

From ISOGG Wiki

X-chromosome testing, ranging from about 16,000 to over 28,000 SNPs (Single-nucleotide polymorphism), is included by default in popular autosomal DNA tests like those from 23andMe, AncestryDNA, Family Tree DNA's Family Finder test, Living DNA, MyHeritage, and others. See the ISOGG autosomal DNA testing comparison chart.

However, the ways in which information about the X-chromosome is reported differ from company to company. 23andMe count the amount of X-chromosome sharing in the evaluation of total centiMorgans shared between two individuals, while the other testing companies do not. Family Tree DNA provides a list of X-chromosome DNA matches but X-DNA matches are only reported if there is already an autosomal DNA match.

The other companies include X-DNA SNPs on their microarrays but do not provide any X-DNA reports or matches.

X-DNA can be independently analysed at third-party tools such as DNA Painter and GEDmatch. At GEDmatch you can also search for X-DNA matches.

X-chromosome inheritance

A number of family history programs such as Family Historian (version 7.0 onwards) include X-DNA charts generated from your family tree. WikiTree users can generate various DNA ancestors reports which include a list of all the ancestors who have contributed an X-chromosome and the average percentage shared. DNA Painter offers a number of family tree visualisation tools including X-DNA inheritance charts.

There are also a number of free charts available online:


Further reading

Scientific papers

Blog articles

See also