Why are transplant between identical twins be more successful than fraternal twins?

Answer 1

I am in the medical field, and if you need a little more detail....Read on down:

Identical twins share an IDENTICAL genotype (genetic make-up). They were the result of a split into two human beings of ONE egg. All of the information on that egg was equally divided to create two people that are identical. The success of ANY transplant is based on how close you can match the genetics. That is why they take samples of blood and marrow, etc., to test. When you are planning to donate organs, they try to type and match the organ to the recipient.

Fraternal twins share FAMILY genetics, but not identical genetics. Family that can donate is desired for being "as close as you can get", very often, but Fraternal Twins do not share the exact same genotype. Fraternal twins are from TWO SEPARATE eggs, fertilized by two different sperm. Each egg and sperm carries different information genetically, and the possibilities are endless as far as creation of a human being, because you have eons of genetic history passed down. It is even possible that Fraternal twins--as with any family member--may not be a good match for a recipient.

At any rate...with Identical Twins, a transplant is more likely to be successful because it is like taking an organ out of one of your "selves" and putting it back into yourself. It should be a perfect match, and identical to the organ that is being replaced.