Re: The system detected me an half-sister that I don't know - A mistake is it possible ?

[aurelienduv]

Hi everybody,
it's my first message on this forum. So I apologize in advance if this topic is on the wrong channel

I receive yesterday a notification of myHeritage for a new user with who I should have a relation, an half-sister. We are in the same country, similar age so it's confusing.
We didn't know each other but by chance we had a call and we used Geneanet to upload our data raw. And this website also say us that we have a relationship, little less that in myHeritage but still positive:
27.29 % (Shared DNA - 2009.1 cM) Shared segments: 28, Longest segment: 247.8 cM

We don't find any relation between us when we are looking to the history of our family.

I need to precise that she found a cousin in the side of her mom, I found also relation in the side of my mom in the myHeritage but not the same. So at least it's sur that my mom is mine and her is her.

Is it possible that there is a mistake in the side of the DNA raw which will create a false positive at this level ?
It's very strange.

Thank you in advance

[robjaco]

While we should never say never, the chance that this is a mistake is extremely small. A sharing of 2009 cM is considerably more than the average for an aunt or niece or half-sister relationship between you. If half-sister, then you either have the same mother or the same father. If aunt/niece, then either she is your mother's sister, or you are her mother's sister. (Or could it be a father's sister perhaps ...)

I'm sure you have already thought about the possible ramifications of this, but I would stress this is really a major finding, one that could turn lives upside down. I would be very careful about either of you mentioning it to anyone else, especially parents, until you feel confident you are ready for all possible reactions.

I really hope it will turn into a happy discovery, for both of you and your families! But it's the kind of adjustment that may need time to accept, by everyone involved.

[chazzi44]

First let me say I am now 67 years old. My mom told me when I was a little girl that I had a half sister from my dad and that all she knew was both little girls were born only months apart 1954. She did not know anything more of it. In Nov 2020 MyHeritage notified me that I am a close dna match to a female who turns out to be a living high-profile celebrity. CRI Genetics had sent me the same name many months ago as she was one of 5 notable persons with same Haplogroup L1c2. My father (deceased) has a living sister age 96 and lots of nieces and nephews. My mother (deceased) other than myself I have a living half brother (different father), lots of nieces and nephews. My deceased brother has 18 living children. If my research is correct my half-sister and I are quadruple related. I share her maternal and fraternal grandparents. She shares my fraternal and maternal grandparents. How do I find out for sure. My heart tells me her DNA just might be on this site. It will probably be masked like it is on all the other DNA websites. I reach out to these close DNA relatives but nobody responds back.

: https://www.wikitree.com/treewidget/Brooks-14952/5

[jyb]

All DNA data uploaded to Geneanet are included to the matching process. If you can't find any close relative, it means that no DNA data is matching with yours.