My cousin trying to scam the government claiming minuscule percentage Native American submitted a sample. What did happen was four children he fathered with four women other than current wives found him.

My grandfather did not die when my dad was 4 like we always thought. Instead, he faked his death, walked 1500km to the other end of the country, married a sixteen old girl and had 7 more children. All the while leaving my grandmother to bring up the 6 children he had with her and his 2 children from an earlier marriage. Worst part was that he used the same names for the second batch of kids as his first lot.

The wife and I both got tested. She had an incredible background. North American First Nations. South American. Portugal and all over Europe. It was so cool! When I got mine back it said. You’re Scottish mate.

My kid took the test, and 8 years later, introduced me to a half-sister I never knew I had. My father had remarried and had a son I knew about, but this younger sister took us both by surprise. And the father in all this has passed on, so... I got a sister now!

I actually found out I have the cancer gene from one of these tests (BRCA1) and my whole family was tested as well - my sister, brother and dad all have it too. We now get preventative cancer testing but who knows it could have very well saved one of our lives down the road - not really horror story overall, but when I first found out it was extremely scary as I was just expecting to get some entertaining report back and instead found out I had a serious health condition

I did ancestry dna a few years ago. Found out my father sexually assaulted over 50 women.

Found out that I’m married to my cousin.

one of my best friends called me one day in a panic. she did one with her father for fun. he is not her father. turns out mummy has many skeletons in the closet. bio dad never knew she existed and was SO happy to find her. we now doubt her sister’s father is her father. just a gigantic domino effect of not good.

Found out my Dad isn’t my biological father. My Dad’s sister gave me a DNA test for the holidays. I ended up taking it and discovered I wasn’t related to my aunt, aka not related to my Dad. But I have 10+ half-siblings with whoever my sperm donor dad is. They gaslit me for months saying the results were inaccurate, called me a liar to my sister, all this garbage. Then finally admitted it was true after 6+ months of lying. We now have a terrible relationship.

not me but my coworker found out his bio dad was not who he thought he was. turns out he is one of the many many children of fertility doctor Donald Cline (there’s a Netflix doc about him if you’ve never heard about him)

One of my great-uncles got contacted by a woman who said he was her father, after she took a test through one of those sites. He denied it vehemently, and it caused some strife in the family until it was revealed that it was actually his older brother who was the father. Turns out he was kind of a cad in his youth, and never found out until now.

My mother was one of seven children of an abusive mother and beloved father. Twenty grandchildren (my cousins, my brother and me). Through testing some cousins have determined that at least three of the seven children were not the biological offspring of my grandmother’s husband. We aren’t telling all the other cousins until the last uncle dies (he’s 93).

We always knew my grandma had my dad before she got married but through ancestry we found out she actually had another baby, after my dad but before she got married (different dads)

My sister found out that half our mom's side of the family, are products of incest. Up and until, a few great aunts and uncles.

Not a horror story, but certainly unexpected… My sister did 23andme and matched with a niece. Apparently my brother 40m, unbeknownst to him, has a daughter. From her age we can tell she must’ve been born when my brother was in was in high school. The bio mom must’ve given her up for adoption without telling my brother. No bad feelings, they would’ve been so young (like 15 years old), so it was for the best.

My best friends Father is my Father. We were 40 when we found out. We were born seven months apart meaning her Mother (my Mom’s best friend) was very very pregnant when I was conceived.

I thought I was all French...Turns out I'm very....ENGLISH!!!!

Finding out they were hacked revealing ancestry, DNA data, birth dates, locations and profile pictures.

My parents and I all did dna tests and I manage their profiles- theirs were done before mine was available. They each got a panicked message from a woman on the other side of the world who had matched as their daughter. She was distraught, thinking her parents had lied to her for her entire life. When I logged in to my account, it showed that I had no dna matches with my parents which I knew to be wrong, plus the fact my mum was a young child when this woman was born made it clear the company had swapped our results. Customer service just said ‘oh well’ and offered a new test. My family found it funny but that poor woman who had spent several days freaking out thinking her life was a lie before I got her messages and responded.

My maiden name is extremely German sounding but I have not a trace of German blood. I match with people with my maiden name so my paternity is not in question but somewhere something is amiss. I have my family tree documented back to the 1500s in Germany so maybe someone was adopted or illegitimate and it’s just not documented.