Phil and Jessica are young adults that want to start a family of their own. Phil was born with polydactyly, which caused him to have an extra finger at birth that was subsequently removed when he was a toddler. This is a dominant condition, which means that only one copy of the mutant gene that causes polydactyly needs to be present to cause the syndrome. Because Phil has polydactyly he realizes that his children have a 50% chance of inheriting the condition. While polydactyly results in extra digits, it does not cause other side effects or health concerns. Usually the extra digits can be removed surgically.
Both Phil and Jessica have carrier screening done and find out they are not at risk for passing on any diseases or conditions to their offspring excepting polydactyly. They pursue preimplanation genetic diagnosis (PGD) to ensure their children will not have polydactyly. The PGD procedure involves removing eggs from Jessica and sperm from Phil, combining them in a dish, allowing the resulting embryos to develop for a few days, genetically testing the embryos, and then implanting selected embryos into Jessica.
Six embryos result from the procedure.
After genetic screening the doctors determine that the embryos produced are all healthy, but all carry the mutation for polydactyly. Now Phil and Jessica are forced to make a decision. Do they implant one of their embryos knowing it has inherited polydactyly, or do they try again, and hope for an embryo without polydactyly? Additionally, it is unclear what will happen to the six embryos if Phil and Jessica decide not to implant them.