- By: Jananam
- March 17, 2025
7 Gene disorders that PGD can detect
Preimplantation genetic diagnosis can detect a range of single-gene disorders in an embryo before transfer, including cystic fibrosis, sickle cell disease, thalassaemia, Huntington’s disease, Tay-Sachs, haemophilia and Duchenne muscular dystrophy. Testing is done on cells taken from the embryo in the laboratory, so only embryos unaffected by the specific condition being screened for are transferred.
What is PGD?
Preimplantation genetic diagnosis tests embryos for a specific inherited condition before transfer. A few cells are taken at the blastocyst stage and analysed while the embryo remains frozen. It is planned around a known condition rather than used as a general screen.
Read this article to know about the genetic diseases that you can pass on to your child.
Pre-implantation genetic diagnosis (PGD) is a reproductive technology that allows genetic health testing prior to embryo transfer. As the name implies, PGD involves genetic tests performed on an embryo that has not yet been implanted in the womb so they can be analyzed, and then if any abnormalities are detected than can be remedied before implantation.
We have listed out a few of them for you here-
- Cystic fibrosis
Your digestive system, lungs, and other organs might become damaged by cystic fibrosis. It’s a hereditary condition brought on by a damaged gene that can be passed down through the generations. The cells that make mucus, perspiration, and digestive fluids are impacted by cystic fibrosis. A child needs two copies of the CF gene, one from each parent, in order to have the condition.
- Tay-Sachs disease
Tay-Sachs is a rare genetic illness inherited from one parent to the next. It results from the lack of an enzyme that aids in the breakdown of fatty compounds. These fatty compounds, known as gangliosides, accumulate to toxic amounts in the brain and spinal cord and impair the nerve cells’ ability to function. By the age of 4, Tay-Sachs babies generally develop pneumonia-related complications. There is no cure for it, for couples who could be at a higher risk of having a child with Tay-Sachs, genetic testing is available.
- Spinal muscular atrophy (SMA)
Motor neurons, the nerve cells in the brain stem and spinal cord that regulate necessary skeletal muscle activity like speaking, walking, breathing, and swallowing, are gradually destroyed by this group of hereditary diseases, which causes muscle weakness and atrophy.
- Hemophilia
Also known as “The Royal Disease”, this genetic disorder causes the blood to not clot properly. This may result in both spontaneous bleeding and bleeding after injury or surgery. Blood contains a variety of clotting proteins that can aid in the prevention of bleeding. Bleeding is more likely to happen when the blood clotting factor level is low, in the case of hemophilia. Currently, there is no treatment for it, however, people can take medication.
- Sickle cell disease
Red blood cells twist into a sickle shape as a result of Sickle cell disease. A scarcity of healthy red blood cells results from the cells dying too soon (sickle cell anemia), and the cells might obstruct blood flow and cause infections, pain, and fatigue (sickle cell crisis).
- Duchennes muscular dystrophy
A heritable condition that causes gradual muscle weakness, usually in boys. Duchenne syndrome is prevalent among those who have muscular dystrophy. Although the condition primarily affects boys, girls can be carriers and have minimal symptoms. Frequent falls, difficulty standing or moving quickly, a waddling gait, large calves, and learning impairments are among the symptoms.
- Thalassemia
This is a genetic blood illness called is characterized by abnormally low levels of the oxygen-carrying protein hemoglobin and red blood cells. Symptoms include fatigue, weakness, pallor, and delayed growth are among the symptoms.
In the end, we hope that you have become better informed about the disorders that Pre-implantation Genetic Diagnosis can detect. If you are a family that is struggling with infertility and suspect you could be carrying an inheritable disease, then we hope that you visit your doctor and explore whether or not a Pre-implantation Genetic Diagnosis is right for you!
References
- Kane, S. C., Willats, E., Hyett, J., & da Silva Costa, F. (2016). Pre-implantation genetic screening techniques: implications for clinical prenatal diagnosis. Fetal diagnosis and therapy, 40(4), 241-254.
- Palini, S., De Stefani, S., Primiterra, M., & Galluzzi, L. (2015). Pre-implantation genetic diagnosis and screening: now and the future. Gynecological Endocrinology, 31(10), 755-759.
Which genetic disorders can PGD detect?
How is the testing actually done?
A few cells are removed from the embryo at the blastocyst stage and analysed while the embryo is frozen. Only embryos unaffected by the condition screened for are considered for transfer, and the biopsy is performed by an experienced embryologist.
Does PGD test for every genetic condition?
No. It tests for the specific condition it is set up to detect, which must be identified in advance, usually because it runs in the family. It is not a general screen for all possible disorders.
Is embryo biopsy safe?
Performed at the blastocyst stage by a skilled embryologist, it is considered very safe, and studies have not shown it to harm the embryo’s developmental potential. It is still a procedure with a small risk, which is why it is done for a defined reason.
Who should consider PGD?
Couples where one or both partners carry a known inherited condition, where a previous child is affected, or where there is a family history of a specific single-gene disorder. Genetic counselling normally precedes the decision.
Does PGD guarantee a healthy baby?
No. It substantially reduces the chance of transferring an embryo affected by the specific condition tested, but no test covers everything and none is perfect. Prenatal screening during pregnancy is still recommended.
Is sex selection permitted in India?
No. Sex determination and sex selection are prohibited by law under the PCPNDT Act 1994. Genetic testing here is used to screen for disease, and clinics operate strictly within that restriction.
Genetic testing sits alongside the rest of a treatment plan rather than apart from it. It is carried out during IVF, and where a genetic cause of male infertility is suspected, chromosomal karyotyping may be advised first.
Related reading
Clinical references
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