Identical twin sisters who married identical twin brothers have welcomed two baby boys into the world - who are both brothers and cousins at the same time. Briana and Brittany Deane, 25, wed Jeremy and Josh Salyer before both couples fell pregnant within just months of each other last year.
Brittany gave birth to Jett, who celebrated his first birthday in January, while Briana welcomed son Jax who turned one in April. Genetically, the two babies are considered "quartenary twins" - meaning they' are both cousins and brothers according to their DNA, according to the Mirror.
Posting to their shared Instagram page, two families broke the news of the biological phenomenon with their 219,000 followers. Explaining the science behind it, one user commented: "Identical twins share the same DNA. When two sets of identical twins marry, it makes their kids genetic sibling."
