Babies born to identical twin parents are cousins — and genetic brothers too
Global News
Little Jett and Jax Salyers, baby boys born to separate sets of twin parents, are known as 'quaternary twins.'
If twin brothers marry twin sisters and both couples have babies, what does that make their offspring? Cousins? Siblings? Both?
It’s a bit of a brain tickler, for sure, and one that’s playing out in the United States.
Identical twins Briana and Brittany, 35, met identical twins Josh and Jeremy Salyers, 37, at the 2017 Twins Days Festival in Twinsburg, Ohio. The girls fell for the boys, were proposed to side-by-side, and returned to the Twin Days Festival the following year to be married in a joint wedding.
Fast-forward a few years, and the sisters each had a baby — albeit three months apart. (Not everything can be totally in sync!)
“You’ve heard the term Irish twins and you’ve heard identical twins and fraternal twins,” Briana Salyers told NBC’s Today. “But we have quaternary twins.”
Quaternary twins are defined as the offspring born less than nine months apart to two sets of identical siblings. They don’t share a womb, or even a parent, but the DNA they inherit from their twin parents makes them not only cousins, but genetic brothers.