I recently found 6 siblings 4 who are half and 2 who may be full.

My sister was born in 1949, I was born in 1950 and my brother in 1952. The other siblings all know who both their parents are. The three of us were adopted by different families. We all have the same birth mother but we can only guess as to who our birth father might be.

As far as I can tell on Ancestry his line no longer exists, unless there are a few more children out there not yet discovered. The three of us are very interested to know if we are full siblings or half. I am confused by all the companies offering tests, and the 3 types of tests. What test would give us the most accurate result.

  • Have any of you had any DNA tests? Do all 6 of you have the same mother? Sep 22, 2018 at 17:43

1 Answer 1


The easiest way to see if you are full siblings or half-siblings is to take an Autosomal DNA test (Ancestry, myHeritage, familyTreeDNA, 23andMe). If you are half-siblings, you will have on average 25% shared DNA versus 50% for a full sibling. A useful resource for determining possible relationships is the shared cM Project https://thegeneticgenealogist.com/2017/08/26/august-2017-update-to-the-shared-cm-project/

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