about chimeras and more

I learned about Blaschko's Lines which led me to read about chimeras who carry two sets of DNA because they are made up of two embryos that fused at some point during development. Chimeras are made up of four parent cells (two fertilized eggs or early embryos fused together. Then, I read about Lydia Fairchild who is a chimera -- and it nearly cost her custody of her children. Despite my fascination with medical mysteries and with conjoined twins, I never watched the television show about Fairchild called "I Am My Own Twin." Incredibly fascinating, even if I don't understand much of the genetics.