Pre-implantation genetic diagnosis (PGD) is a technique that enables people with a specific inherited condition in their family to avoid passing it on to their children. It involves checking the genes of embryos created through IVF for this genetic condition. Before PGD clinics are permitted to test for a condition or combination of conditions, the HFEA must first agree that the condition they want to test for is sufficiently serious. This list of conditions are those that the HFEA has so far agreed that it is acceptable for clinics to use PGD to test for.