Genetics play an important role in our health, particularly when it comes to inheritable diseases. Some diseases are ones that are passed down from one generation to another, and thanks to genetic testing we can decrease our risks of having offspring affected with these diseases.
Genetic carrier screening is a test looking to see if you’re at risk of passing down any genetic diseases to your children, particularly ones that cause severe or life threatening conditions. Being a carrier means that you inherited one gene with an irregularity (called a mutation) from one parent and a normal gene from your other parent. What many people don’t realize is that for these recessive disorders, people don’t have any signs or symptoms of the disease, and in many cases no family history of it either. This is because recessive disorders require TWO copies of the affected gene to manifest symptoms, and if you’re a carrier for it (meaning only 1 abnormal copy) you wouldn’t have any symptoms of it.
If both parents have a mutation for the same (recessive)gene, then one in four (25%) of their pregnancies will inherit a mutation from each parent, resulting in two gene copies and risk of the condition. Examples of these recessive conditions include Cystic Fibrosis, Spinal Muscular Atrophy and Tay Sachs disease to name a few.
Additionally, some are X-linked conditions, where only the female partner needs to carry a mutation for her children to be at risk, i.e., Fragile X - a major cause of developmental delay in boys. These X-linked disease carrier status results in a 50% chance of having a boy affected with these diseases.
So how does knowing this information help? If your results indicate that you do have an elevated risk of having a child affected with an inheritable condition, you may have the option to pursue In Vitro Fertilization (IVF) with Preimplantation Genetic Testing (PGT). This allows for the embryos to be screened to determine which ones are at risk of having the inherited condition. The testing involved in determining this may require additional planning prior to the start of your IVF cycle, so knowing this prior to starting treatment can help optimize your outcomes.
For patients opting not to undergo IVF to conceive, patients who conceive on their own may have the option of testing the fetus while pregnant to determine if it is affected by the condition or not, via some invasive prenatal testing called amniocentesis or chorionic villi sampling.
Undergoing genetic screening prior to getting pregnant or starting treatment provides patients with information needed to take the appropriate steps to optimize their outcomes. More questions? Consider scheduling a preconception consultation with a Fertility Specialist to discuss your genetic testing options.
