What’s in Your Genes? Why Genetic Carrier Screening is requested by your Reproductive Specialist
When You meet with a reproductive specialist to learn more about your fertility care options, one of the first steps in the journey involves the collection of numerous blood samples for analysis. The number of tubes of blood collected may seem overwhelming and you may ask yourself, “What are they looking for and why so many vials?” The bloodwork analysis can help share very important insights regarding your health and fertility potential that can aid your reproductive physician provide You with more efficient care.
One of these many blood tests is likely is to examine your DNA makeup and to see whether any abnormalities exist within your genes. Genetic Carrier Screening investigates whether You might be a carrier for one of numerous genetic disorders that could affect your future off-spring. Such screening is recommended by the American College of Obstetrics and Gynecologist for all women who are either pregnant or planning for pregnancy.
Every individual has two copies of each gene; however, for Carriers, instead of two normal copies they have one normal copy and one abnormal copy. These abnormal copies of genes can lead to a genetic disorder. Some genetic disorders are relatively common no matter one’s ethnic background such as Cystic Fibrosis (CF), Fragile X Syndrome and Spinal Muscular Atrophy (SMA). While other disorders are more specific to particular ethnicities such as Alpha-thalassemia, Beta-thalassemia, Sickle Cell Disease, Tay-Sachs disease and more.
What if You are a Carrier?
Most Carriers don’t even realize they are one. They live healthy lives and are not aware of any prior family history of a specific genetic disorder. Just because you are a Carrier for a specific disorder doesn’t imply that your off-spring will be impacted. There are two methods by which a genetic disorder may be passed on to one’s child:
- Autosomal Recessive Inheritance
- X-Linked Inheritance
With Autosomal Recessive Inheritance, a child inherits a genetic disorder from both the mother and the father. While an X-Linked Inheritance occurs when a male inherits an X-Chromosome with a genetic causing variant from the mother.
What are the Risks Your Child Will be Affected?
In situations where both You and Your reproductive partner are carriers for the same autosomal recessive genetic condition the risk is as follows:
- 1 in 4 (25%) chance of having a child affected with that genetic disorder
- 1 in 4 (25%) chance of having a child who is not affected by the disorder and not a carrier
- 2 in 4 (50%) chance of having a child who is a carrier of the disorder
In situations where a female is identified as a carrier of an X-Linked condition, there is a 1 in 2 (50%) chance to pass the genetic disorder to her child. If a male child inherits the disorder he will be affected with the X-Linked condition.
What are Your Options?
If it is discovered that You are a Carrier additional genetic carrier screening may be requested for your reproductive partner. Genetic counselors are available to discuss your results with you and the potential impacts that may arise to future off-spring. In the event of an increased risk of passing along a specific genetic disorder to off-spring is present, In Vitro Fertilization with the use of Preimplantation Genetic Diagnosis (PGD), may be the recommended course of treatment.