Preimplantation genetic testing in the form of PGS (preimplantation genetic screening) and PGD (preimplantation genetic diagnosis) is being increasingly adopted by IVF clinics. This genetic testing is aimed at identifying genetic disorders that might be present within the IVF embryos created for implantation. Using PGD and PGS, the IVF facility can isolate the healthier embryos, exponentially raising the chances of establishing a genetic disorder-free pregnancy. However, one notable use of such embryonic testing has come forth in the form of HLA or Human Leukocyte Antigen (a part of the human immune system) matching. Its most significant use is as a life-saving measure for saving children with terminal genetic diseases.
How HLA Matching Can Save Human Life
HLA matching is an application of preimplantation genetic testing. It is particularly useful for couples who have a child with a genetic condition that can be treated only through a HPC transplant (Hematopoietic Progenitor Cell transplantation). This is a specialized form of bone marrow transplantation that is financially very demanding and further, chances of finding a suitable donor for HPC transplants are rather low. The main condition for this transplant is that the donor's cells need to be HLA-matched with that of the patient. This is more likely to happen if the donor is a sibling of the patient.
Parents of such a patient can seek IVF treatment and get their embryos genetically tested through PGD/PGS methods for finding a healthy and HLA-matching embryo. When this embryo is chosen, chances are rather high that the resulting child will have matching bone marrow cells to save the life of his sibling.
Note that preimplantation genetic screening doesn't raise the chances of HLA-matching. It only aids in finding an HLA-matching embryo. It is possible that despite repeated attempts, HLA-matched embryos might not be found. Since HLA matching allows HPC transplantation from a family member, costs incurred in the form of seeking a donor and legal hassles of getting registered on donor lists is saved upon.