X-chromosome inheritance patterns – 2049 days old

[Ubirajara]

I have one on 23andme, I share 17cm on the X with her (only segment we match on).

On Gedmatch you can specifically look for matches on your X-chromosome.

[Raez]

Thank you so much for sharing these charts. I'm finding them very helpful! But just to be clear that I understand this correctly ... According to that chart, a woman can not have an X-"cousin" match with someone from her paternal grandfather's family tree. Is this correct?

[JaM]

Thank you so much for sharing these charts. I'm finding them very helpful! But just to be clear that I understand this correctly ... According to that chart, a woman can not have an X-"cousin" match with someone from her paternal grandfather's family tree. Is this correct?

That is correct. Your father get his X chromosome from his mother, not his father, so you only inherit the X from your paternal grandmother - unless they or your parents were related, which is not uncommon - we all have single ancestors on multiple lineages.

[Kriptc06]

X inheritance is different from other chromossomes. I have tested my maternal grandmother, who gave her Xs recombined to my mom. yet I got only 21.1 cM shared with my grandmother, that is roughtly 11% of her Xs. So 89% comes from my maternal grandfather.
(according to gedmatch the size of the X is 190.1 in cM)

[a_garcia49]

So I found a match on GEDMatch with total/largest 20.1 shared CM on X, but nothing on autosomal, is that basically a very distant relation?

[Kriptc06]

So I found a match on GEDMatch with total/largest 20.1 shared CM on X, but nothing on autosomal, is that basically a very distant relation?

yes, that can happen, so distant that you have no Au anymore. like my case I got roughly 89% from my maternal grandfather, who got both of his mothers recombined, and her got one from her mom, one from her dad so on. so I can have a X bit from 5-6 generations ago on my granfather side, that would be 1 to 3% of Au, that I could not inherit by chance.