I grew up in a household with half siblings. Same mother different fathers. I grew up never knowing who my dad was. As I got older I started to ask questions. My mother would push back with resistance. I have talked to my mother's sisters and brothers as well, to try and find out anything about my dad and his family. No help there. Everyone is very vague about it all, lots of secrets and secretive talks amongst the elders.

Last year, 2019, I used the DNA kit from 23&me trying to uncover some information there. Now, the surnames of immediate family begin with B, J, K and M. 2 sisters who share the same father, are Bs, 1 brother different father J, then myself, K, my baby brother is an M because of an unknown father. Now the Js and Ks are distant in relation. And my two sisters, when I search the B surname it pops up quite a bit, through another surname name of N. There are a host of other surnames, but I'm starting with what I have been told.

Here is where my questions are. If I am a half sibling of my B sisters, would their relatives show up in my genealogy lineage?

Also the surnames of J and K?

Where would they essentially come into play if my brother is a J would that be some of his relatives?

And the long lineage of K, if I am suspected of being a B.

I'm very new to this DNA process and trying to break it down I guess to see if I am indeed a B and how to move forward.


2 Answers 2


If I understand your correctly, "father K" is your biological father and not the biological father of your B, J and M half-siblings.

It is possible that your biological relation to your half-siblings is more complicated and unexpected than just half-sibling. There are two ways an unusually high amount of your DNA matches DNA from father B or J or M and their relatives:

1) your biological father K is related to father B or J or M 2) your biological mother is related to father B or J or M

Similarly, there are two ways an unusually high amount of DNA from your half-siblings matches DNA from your biological father K and his relatives:

1) your biological father K is related to father B or J or M 2) your biological mother is related to your biological father

Keep in mind that the relationship between your mother and one of the fathers (including yours) might be socially frowned upon. It might be embarrassing like father B/J/M/K is an uncle or first cousin of your mother or it might be extreme such as father B/J/M/K is your mother's father. There are many possible unexpected relations between your mother and the fathers with varying degrees of shame. So investigate with care.

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    Yes you are correct. We are all half siblings. Different fathers. What an interesting thought provoking spin on what you stated here. Considering how hush hush my mom and her siblings have been, this doesn't seem too far fetched. Thank you! Mar 7, 2020 at 19:06

You didn't mention if you are male or female, but it does matter. The type of DNA you can inherit, and therefore assumptions you can make, is determined your gender.

If you are male, then you will have Y-DNA that matches your father, and any brothers that share the same father.

If you are female, then you will will inherit the non-Y-DNA half of your father. See Diahan Southard's lecture on "How DNA Influences Our Identity" (currently free) https://familytreewebinars.com/diahansouthard She discusses how a pair of sisters thought that they had different fathers but through DNA testing were able to show that they had the same father.

You also don't mention which of your siblings or their fathers have had their DNA tested, which should help in identifying potential matches. You might consider contacting a specialist in genetic genealogy to help you map out and interpret your results.

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