Could DNA matches of 1,591 and 1,773 cM be half siblings of person tested?

Question

I recently received my DNA matches from Ancestry, and I share 1,591 centimorgans across 53 segments with one, and 1,773 centimorgans across 58 segments with another.

Could these people be half siblings to me?

Answer 1

Yes.

DNA Matches of 1,591cM and 1,773cM indicate half siblings as being a possible relationship.

On the strength of those matches the two people could also have one of these relationships to the person tested:

• Grandparent/Grandchild
• Aunt/Uncle/Niece/Nephew

but perhaps these can be ruled out on what you know of your family's generations.

Answer 2

Use The Shared cM Project 4.0 tool v4 that may be found on the DNA Painter website.

You can enter the number of shared CMs and see all the possibilities for how you are related to each of the matches.