If I am a carrier, what is the risk that my children will inherit the condition?
If both you and your reproductive partner are carriers of the same autosomal recessive condition, with each pregnancy you have a:
- 1 in 4 (25%) chance of having a child affected with that disease
- 1 in 4 (25%) chance of having a child who is not affected by the disease and not a carrier
- 2 in 4 (50%) chance of having a child who is a carrier of the disease
If a woman is identified as a carrier of an X-linked condition, she has a 1 in 2 (50%) chance with each pregnancy to pass on the variant to her child. If a male child inherits the disease-causing variant, he will be affected with the X-linked condition.
If I receive a negative result, does that mean I have zero risk of being a carrier?
A negative result does not guarantee that you are not a carrier, due to the possibility of residual risk. Residual risk is your chance of being a carrier even though you received a negative result. It is based on your ancestry, as well as the ability of genetic testing technology to identify disease-causing variants in a particular gene.
Our Expanded Carrier Screen can identify ancestry information from your DNA, which is used to calculate the most accurate personalized residual risk. Based on your specific ancestry, Sema4 can determine how likely we are to detect disease-causing variants in a particular gene and provide you and your provider with your personalized residual risk information. Your specific ancestry information, however, is not visible to your provider.