Half Sibling or First Cousin (find, search, skin, percentage)
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I just received my DNA results back and one of matches came back showing as "Half Sibling". I have always known this person to be my first cousin (my Dad's brother's daughter). She also showed on my daughter's match as a first cousin rather than first cousin once removed.
The percent we share along with total cm's does not fall in line with first cousin or half sibling so I'm really not sure what to make of it.
This was the result with her and myself....
1365 cM
40 segments
18.3% DNA Shared
This is the result with her and my daughter.....
668 cM
25 segments
8.98% DNA shared
If someone has more knowledge about amounts and relationship I would love to have your thoughts on this!
An adopted relative who is pursuing biological roots ran into this. My relative met the other individual, who was also pursuing their history, and compared notes. Turned out they were half-siblings rather than first cousins, each separately placed for adoption at birth by their bio. mother in the early 1950s, when adoption records were more hush-hush. In each case, their adoptive families had told them what was known - but it wasn't entirely accurate.
Apparently half siblings and first cousins' DNA percentages can be very, very similar. I would assume that your supposed cousin is just that, your first cousin.
On my results, under my first cousin category is my half-aunts. (My dads half sister and my moms half sister) Along with my maternal grandmother's sister (My great aunt.) But, yes, it is a first cousin, because half siblings show up as close family, not first cousins.
I just received my DNA results back and one of matches came back showing as "Half Sibling". I have always known this person to be my first cousin (my Dad's brother's daughter). She also showed on my daughter's match as a first cousin rather than first cousin once removed.
The percent we share along with total cm's does not fall in line with first cousin or half sibling so I'm really not sure what to make of it.
This was the result with her and myself....
1365 cM
40 segments
18.3% DNA Shared
This is the result with her and my daughter.....
668 cM
25 segments
8.98% DNA shared
If someone has more knowledge about amounts and relationship I would love to have your thoughts on this!
Question. Who did the test? Ancestry? FTDNA? 23andMe?
Every Company has different "interpretation" on this.
My brother's son is on every company as well, just like me, and the results are the same but the "interpretation" is different. At FTDNA he is "half sibling" while in other he is my Nephew.
Different companies not only report different possible relationships, but also they typically report a different total amount of shared DNA. This is because some of them filter out segments below a certain threshold and some don't, and even when they do, they have different thresholds. AncestryDNA often has a lower reported amount of total shared DNA because they have a system called Timber that filters out what it considered irrelevant segments, but in my personal opinion it can be a little overzealous sometimes. Meanwhile, FTDNA's totals are often inflated due to the fact that once someone meets the minimum thresholds to qualify as a match, they include all shared segments in the total, even ones that are small enough to not be identical by descent (you can have identical by state segments even when a legit match who is identical by descent). I can't remember off the top of my head where 23andMe falls with this, but I want to say they do something similar to what FTDNA does and include smaller segments in the total once someone qualifies as a match.
Often in situations like this, it's encouraged for everyone to upload to Gedmatch.com and run a one-to-one comparison there. Their default thresholds are usually more middle-of-the-road and may give you a more accurate total amount of shared DNA.
Here is my FTDNA results about my nephew: Half Brother, Grandfather/ Grandson, Uncle/ Nephew
He is just my Nephew at Ancestry and many other DNA companies.
Here is my FTDNA results about my nephew: Half Brother, Grandfather/ Grandson, Uncle/ Nephew
He is just my Nephew at Ancestry and many other DNA companies.
AncestryDNA does not report a nephew as a nephew. These are the relationship categories they include:
Self/Identical Twin
Parent/Child
Immediate Family
Close Family
1st Cousin: possible range: 1st – 2nd cousins
2nd Cousin: possible range 1st – 2nd cousins
2nd Cousin: possible range 2nd – 3rd cousins
3d Cousin: possible range 3rd – 4th cousins
4th Cousin and more distant
So he is probably estimated as Close Family, and the range is probably Close Family - 1st cousin.
"A close family relationship could range from two to four degrees of separation. Close family could be an aunt or uncle, niece or nephew, great-grandparent or great-grandchild, a half-sibling, or a double-first cousin. Someone who appears in this category is rarely a first cousin."
Most companies include an estimated relationship range too, but it's really best to look at how much DNA in cMs or percentage you share rather than trying to go off the estimated relationship.
To answer a few questions.....this was on 23andMe. I have also upload my raw data to Genesis Gedmatch and also have it uploading on MyHeritage (they take forever). Since it is v5 I can't upload it to FTDNA. I don't feel comfortable asking her to upload hers though. I just wanted to check to make sure my husband and I weren't related......lol!
I did some more researching tonight and it does appear that first cousins that have father's that are brothers usually have a higher chance (versus two sisters or sister/brother) of having much more or much less than the average. However 18.3% with 1365 CM's still seems a little high to me.
I might ask my father to do a test. Not necessarily for this reason but it still would be interesting to see what his shows in relation to me and to her. Plus I'm more interested in being able to know who the shared matches align with (mom or dad side). I really don't plan on telling anyone about this since most likely it is nothing. And even if it was.....my Dad is a very old man and no need to bring this up at this point and time.
I can tell you though that I am having fun with all of this! I also find it interesting that many of the people we have encountered on the shared DNA lists really don't want to share much info however they would love for you to share yours. I don't understand that mentality.
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