Pre-Implantation Genetic Diagnosis (PGD) is a specialized diagnostic procedure used in conjunction with in vitro fertilization (IVF) to determine genetic abnormalities in an embryo before it is implanted into the uterus.
PGD enables couples who carry genetic diseases to have biological children without passing on those inherited diseases and disorders. It also allows older women undergoing IVF treatment to increase the odds of having a healthy, genetically normal fetus.
PGD has its roots in the 1980s when it was first developed as a test to identify genetic disorders in embryos for couples at risk of passing on a genetic disease to their children through in vitro fertilization.
It has grown in significance and popularity in recent years as an increasing number of people turn to IVF as a way to conceive children.
Understanding the Process of PGD
PGD is a two-step process that involves IVF and genetic testing of embryos. The first step of the process is to perform standard IVF procedures to create fertilized eggs.
The next step is to remove one or two cells from each embryo and test them genetically to detect any chromosomal abnormalities, genetic diseases, or conditions that increase the risk of certain medical conditions in a child.
The genetic testing process can be done using various techniques like Fluorescence in-situ hybridization (FISH), Polymerase chain reaction (PCR), Comparative genomic hybridization (CGH), and Next-generation sequencing (NGS).
The choice of technique depends on the specific condition being tested for and the particular laboratory performing the test.
Conditions Diagnosed by PGD
PGD can detect a variety of genetic disorders and chromosomal abnormalities in embryos. The test can detect single-gene disorders like cystic fibrosis, sickle cell anemia, Huntington’s disease, thalassemia, and Tay-Sachs disease.
It can also detect chromosomal abnormalities like Down syndrome, Turner syndrome, and Klinefelter syndrome.
PGD can be used to screen for aneuploidy, which is characterized by abnormal numbers of chromosomes in an embryo.
The most common aneuploidies diagnosed by PGD are trisomy 21 (Down syndrome), trisomy 18 (Edwards syndrome), and trisomy 13 (Patau syndrome).
Who Should Consider PGD?
PGD is recommended for couples who have a high risk of passing on a genetic disease to their children, such as couples who have a family history of a genetic disorder.
It is also recommended for women who are older because the risk of chromosomal abnormalities in embryos increases with age.
Related Article
The Miraculous Techniques of Pre-Implantation Genetic Screening
PGD is a valuable diagnostic tool for couples who have experienced several miscarriages, repeated IVF failures, or for those who are carriers of a genetic mutation that may affect their offspring’s health.
It is not recommended for couples who are fertile and have a low risk of transmitting a genetic disease or chromosomal abnormality to their children.
Benefits of PGD
The primary benefit of PGD is that it enables couples at risk of passing on a genetic disease to have biological children without passing on the disorder.
PGD has proven to be a useful test for identifying chromosomal abnormalities, single-gene disorders, and other genetic conditions in embryos. It can help doctors identify healthy embryos for implantation and improve the overall success rate of IVF.
The test can also help identify the sex of an embryo, which can be useful for couples who want to avoid having children with a specific sex-linked genetic disorder or for balancing the gender of their children.
Limitations of PGD
Despite the numerous benefits of PGD, it has some limitations. One significant limitation of the procedure is that it is not 100% reliable and may produce false-positive or false-negative results.
Scientists are continuously working to improve the accuracy of the test.
PGD can also be costly, and it is not covered by insurance in all cases. The cost of PGD varies depending on the lab, clinic, and the specific tests being performed.
Patients should consult with their doctors to determine if the procedure is covered by insurance and what out-of-pocket expenses they may incur.
The Future of PGD
As technology advances, the use of PGD is likely to increase and become more precise. Newer tests like NGS have the potential to revolutionize PGD by giving scientists the ability to decode an embryo’s entire genome sequence accurately.
This will provide a more detailed understanding of the risks associated with certain genes and will potentially allow for more accurate diagnoses of genetic conditions and diseases.
PGD offers many benefits to couples struggling with infertility, and it is a valuable tool to aid in the selection of healthy embryos for implantation.
As research and development continue to improve the technology, PGD holds the promise of a brighter future for those seeking to conceive healthy children.
