Can there be features for X chromosome matching?

Question

23andMe reports X chromosome matching with other 23andMe customers.  Family Finder does not yet report X chromosome matching but they should soon.  GEDmatch does report X chromosome matching for everyone who has uploaded from 23andMe, Familly Finder, and I believe AncestryDNA.

 

I suggest WikiTree  allow people to see a chart of their ancestors who could contribute to their X chromosome (these charts are different depending of the sex of the test taker).  Also it would be helpful to see a descendant chart for all persons who could have inherited a particular ancestor's X chromosome.  This will be very helpful in understanding the X chromosome matching one currentlly finds in GEDmatch or 23andMe.

 

Thanks and sincerely, Peter

Comments

Update: The X-chromsome is now included on the DNA ancestor view.

For example, here's Peter's.

We'll add it to the descendants view soon.

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Looks interesting.

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The X chromosome is more helpful than i imagined and WikiTree has made it so much  easier to use. In GEDmatch I sorted my one-to-many X chromosome matches from  largest to smallest for myself and also for my maternal uncle.  Then I e-mailed each match for my uncle (and also for myself).

Hello xyz,

 

You ( kit M123456) and my maternal uncle (kit F15373) are a 14.5 cM X chromosome match in GEDmatch.  His known ancestors who could have contributed to his X chromosome are at 

 

http://www.wikitree.com/treewidget/Dekle-6/89

 

under X-Chromosome

 

Please let me know if you have any of those same ancestors 

 

Thanks and sincerely, Peter

 

>>>>>>>>>>>>>

 

The response has been great.  One of my X-DNA cousins has Miller ancestry and other has Williams ancestry.  I've not done this before because generating an  accurate chart I could easily share of those X-DNA ancestors was too much trouble.

 

Thank you WikiTree!

 

 

 

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Peter, this is great! It really makes me happy and proud that it's already being useful.

I was thinking we should write up some recommendations for how people can use WikiTree tools when contacting matches at GEDMatch and the various testing companies.

Maybe we could use your message here as a suggested template. Not sure if it would go on http://www.wikitree.com/wiki/Project:DNA/GEDMatch or elsewhere.

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This is great, thanks wikitree!  I stumbled on it tonight when updating DNA info!

Answer 1

As a FTDNA customer, I haven't yet had any experience in looking at the X chromosome , but it would be great to be ahead of the curve if it is being introduced soon!  I would support the idea.  The more tools we can get the better it will be for all.

Comments

FTDNA customers can upload their results to www.gedmatch.com and compare their X chromosome results with other Family Finder and 23andMe  and perhaps AncestryDNA customers who have uploaded to GEDmatch.

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Thanks Peter, I didn't realise that.  I have uploaded to gedmatch for all my accounts but to be honest have only had limited time to 'play' with it.  It has been down a lot when I was available and seems to start working again when I don't have much time!   Hopefully I'll be able to get into it again in more depth at the end of this month.

Answer 2

Family Tree DNA announced today that they plan to have their X chromosome matching / browser available before Jan 1st 2014.   It would be good if WikiTree users  could see a chart of their ancestors who could contribute to their X chromosome (these charts are different depending of the sex of the test taker).  Also it would be helpful to see a descendant chart for all persons who could have inherited a particular ancestor's X chromosome.  This will be very helpful in understanding the X chromosome matching one currently finds in GEDmatch or 23andMe.

 

Comments

Hi Peter,

Definitely! Doing the X-DNA ancestor and descendant charts to parallel the Y-chromosome and mitochondrial inheritance charts makes sense. We'll get started on that ASAP. Later we can look at enabling them to be entered as separate tests, if that makes sense.

Chris

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Here is a fan chart with ahnentafel numbers showing who in the ancestry of a female can contribute to her X chromosome:

http://freepages.genealogy.rootsweb.ancestry.com/~bonsteinandgilpin/images/x-charta.jpg

Here is a chart showing who in the ancestry of a male can contrbute to his X chromsome

http://www.thegeneticgenealogist.com/wp-content/uploads/2008/12/1male.png

There should be a formula for this.

Sincerely, Peter

Answer 3

How do I correlated % with total CM and largest CM?

What does it mean if my next cousins in gedmatch have an autosomal Gen =4 but no X shared. How much can I use this to rule out common ancestors?

Best,

Andreas

Comments

Regarding your 2nd and 3rd questions,  if you have a match which is 7cM or greater then you can be relatively confident the match is real. Not matching on the X does not change that.

If you have an X match then you know which branches of your ancestry and their ancestry the shared ancestor for that segment can't be on.  There is no X inheritance between a father and his son.

Please ask your 1st question in a different way.  Thanks and sincerely, Peter

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Thanks Peter for the reply. I understand that zero shared X cM can be also a filter for unshared ancestors.

My first questions asked in a different way. Gedmatch provides Centimorgans as result. How do I correlate largest segment shared or total centimorgans (meeting threshold constraint) with the percentage you have given based on a family tree.

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Hello Andreas,

The percentages shown along side of the ancestors who could have contributed  to one's X chromosome are an average guideline (individual results will vary;-)

I believe if you have a 9 cM match with someone else then your shared ancestor could  be  anyone a few generations back on your (and their) X chromosome ancestral tree.   The percentages will indicate it is more likely to be from  certain  branches but I would not depend too much on the percentages.

Sincerely, Peter