"When I looked on that page and saw mum for him and father unknown, I thought 'what do you mean father unknown?'"

We've all had pranks that gone wrong, but I don't think I've ever experienced a prank that went this askew. Donna Johnson thought it would be funny to order DNA kits and have her family take them to see if they were related, obviously expecting the results to come back as a resounding yes. The light hearted joke soon turned questionable when it turned out her son wasn't biologically related to his father. Yes, really. When Donna and Vanner Johnson purchased the kits, they hoped it would bring the family closer together, but instead it turned everything up on its head. When the results came back, the couple discovered that their 12-year-old son, who was conceived through IVF, was not biologically related to his father. The shocked couple realised that there must have been a mix up of samples at the clinic, meaning another child out there was biologically Vanner's child. Speaking about the DNA revelation Vanner told the Daily Mirror: "When I looked on that page and saw mum for him and father unknown, I thought 'what do you mean father unknown?' I am his father. "There were a lot of emotions we had to work through including separating the love of our son which has not changed. "This mistake that happened, how could it happen, why did it happen and what do we do now." The clinic that Donna and Vanner attended while trying to conceive their son has since confirmed that there was a mix up, and that Donna was given a stranger's sperm sample. As of the moment, Donna and Vanner have said that they have not told their son about the mix up and probably won't until he is older.