I don’t know how doctors can say twins aren’t hereditary. We have at least two sets every generation on both sides of our family that we know of.

On mom’s side: grandma has twin brothers, George & Benjamin (died at birth). Uncle George had twin girls, Bridget & Brenda. Grandma had twin boys, Eddie & Ellis. Mom had us, twin girls, Stephanie & Vanessa.

On dad’s side: grandpa’s brother has two sets of twins, identical boys, Kenneth & Kellis, and fraternal boy/girl, Paul & Carlotta. Uncle Kenneth has twin boys, Carlos & Juan. Grandpa has twin boys, Jesse & John. Dad has us.

It's kind of scary; our twins have twins (once again, on both sides). I hope it's my sister, not me.