PGD, or preimplantation genetic diagnosis, is used for genetic screening of embryos prepared during IVF. The main application is to identify the possibility of genetic disorders being transmitted to the embryos. This identification allows the removal of embryos suspected of carrying genetic defects, ensuring that a healthier group of embryos is available for implanting. Some alternative uses of preimplantation genetic diagnosis have also come to the fore in recent years.
Treatment of Critical Illnesses
People who suffer from terminal diseases like aplastic anemia or leukemia can be saved only via a bone marrow transplant. This raises the issue of finding a compatible donor. Finding a matching donor is difficult, and the demand for such donors is much more than their availability. PGD can resolve this situation to some extent. It can help in creating a compatible donor. This is applicable to patients who need a donor but can wait for a few years.
In such cases, the mother of the patient needs to undergo IVF. This includes testing the embryos through the PGD techniques. If it is found that the DNA of an embryo is similar to the donor demands of the patient, it can be implanted into the mother. Once the child is born, the stem cells can be surgically extracted and used as a life-saving medium for his ailing sibling.
This application is limited to the waiting period that is possible for the patient. It is not useful for immediate donor requirements. The cost of PGD testing can be more than the norm here, since a large number of embryos might be needed for extensive PGD testing until the ideal embryo (an exact match for the patient's DNA) is identified.
Research-Based Alternative Use of PGD
This is an offshoot of PGD testing measures that is now being suggested to fertility clinics by medical research facilities. PGD testing needs a certain number of embryos. However, it is not necessary that all the embryos are used; there are always some extra embryos that are either destroyed or donated to other IVF couples. Research facilities are increasingly seeking the cooperation of fertility clinics to donate these embryos for research purposes, to create a line of stem cells.
These stem cells are then used for meeting various life-saving requirements as mentioned above or for furthering the cause of human stem cell research. This also erases one of the ethical contradictions against preimplantation genetic diagnosis, i.e., the eradication of unused embryos that is often deemed at par with conscious killing of human life.
Gender Selection Through PGD
This is among the most argued uses of PGD testing which is nonexistent among most fertility clinics. However, it does have an appreciable use in some rare, typical scenarios. PGD testing methods are essentially invasive clinical procedures that can decode most aspects of genetic information within the embryo. This also includes realizing whether the embryo will develop into a male or female child.
This form of genetic sex determination is not approved by most government authorities but it has been applied in some nations where family balancing is the issue. Family balancing issues arise when there are already two children of the same gender in a family. Thus, the parents want to select an embryo belonging to the opposite gender.