Problem
Grandma Judy has a sister who has two children-Sara and Tara that are identical twins. They were married in a double wedding ceremony to two young men they met in college. All four adults were healthy and loved to participate in exercise and athletic competitions. Over the next 2 years, one couple had a baby girl, and the other had a baby boy. Because of a variety of circumstances, the twins and their families rarely saw each other over the next 20 years, and the children grew up without knowing each other. When they were 22, they met at a large family reunion, fell in love, and were married in a quiet ceremony in Las Vegas. Eight months later they were devastated when their baby was born prematurely and stillborn.
Task
i. Draw the pedigree for this family.
ii. Can you anticipate a possible cause for the fetal demise?
iii. What would you explain to Grandma Judy?