My half-sister and I recently completed DNA tests with myHeritage.com. The results don't show us having matching DNA. We share the same father.

Is it possible that we are half siblings even though there is no DNA match?


If you are really half-sibling, and you took the test from correct people, you WILL have a shared DNA. A half-siblings share ~25% of DNA between each other. Or 1300-2300 cM.

The chances that the examples were accidentally mixed in laboratory are very small.


In a prior answer it was stated that you would share between 1200 and 2300 cM of DNA. This is the primary way to validate if you are true half-siblings.

But, you might also want to compare your close matches with the matches that your tested half-sibling shares. Do both of you have matches that are the same DNA donors? If so, you might want to pursue those matches and see how you are related to them (who are your common ancestors). If you don't share any similar matches then it's even more probable that you are not half-siblings.


Yes it's possible - assuming you are both female you will share an entire x chromosone which ancestry and my heritage do not test for - but gedmatch.com does. It's possible to not share any autosomal DNA with a half sibling as hereditary of the same chromosones from a a parent varies even with full siblings. Upload your DNA data on gedmatch if you are sisters and compare you x DNA...of course won't work between male/female siblings. I am curious though if you went that route what did you learn? Are you siblings (I'm going through this right now too)

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    You are completely wrong about this. To quote from the correct answer "half-siblings share ~25% of DNA between each other. Or 1300-2300 cM." – ColeValleyGirl Jul 27 '18 at 17:55

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