What is Genetic Carrier?
Genetic carrier is a person that has a mutant gene of recessive disease who usually does not display or show symptoms of the disease.
Although carriers are healthy, however, they are able to pass the genetic condition onto their offspring, who may then express the genetic trait.
If both parents are carriers of the same disorder, there is a 25% risk that the offspring have the recessive trait in phenotype.
Did you know?
- PLoS Curr. 2012 May 2:e4f9877ab8ffa9
- The American Journal of Human Genetics 91, 1022–1032, 2012.
Why should I do Expanded Carrier Screening?
Most people can be a carrier of a genetic disease without knowing it. If both parents are the carrier of a same disease, they have a 25% risk of having an affected child with a recessive genetic disease and a 50% risk that the child will be a carrier like the parents.
Expanded Carrier Screening is a genetic test used to determine if you are a carrier of a certain genetic condition. It provides life-lasting information about your carrier risk and let you understand your chances of having a child with a genetic disease.
This test is recommended for people who:
- Would like to understand their risk of having a child with a genetic disorder.
- Have a family history of genetic disorder.
- Are considering pregnancy or already pregnant.
- Are closely related by blood (couples with consanguinity).
- Are planning to use/ donate eggs, sperm, or embryos.
Why choose GGA Expanded Carrier Screening?
Disease categories covered:
What should I do if my partner and I both have family history of genetic condition?
If one or both prospective parents have a family history of a common, inherited genetic condition and the couple has decided to undergo carrier screening.
I don’t have a family history of any genetic conditions. Should I still be tested?
Yes. From research, the average individual might carry more than 2 disease-causing gene. Besides, there are more than 80% affected children have no family history. Even if you have other children who are healthy, this cannot rule out the possibility you or your partner could be carriers for a genetic condition.
When can carrier screening be done?
Some people decide to have carrier screening before having children. Carrier screening also can be done during pregnancy. Getting tested before pregnancy gives you a greater range of options and more time to make decisions.
What is a recessive disorder?
Most carrier screening is for recessive disorders. It takes two genes—one inherited from the mother and one inherited from the father—for a person to get a recessive disorder. If a person has only one gene for a disorder, he or she is known as a carrier. Carriers often do not know that they have a gene for a disorder. They usually do not have symptoms or have only mild symptoms.
What are the chances of having a child with a recessive disorder?
If both parents are carriers of a recessive gene for a disorder, there is a 25% (1-in-4) chance that their child will get the gene from each parent and will have the disorder. There is a 50% (1-in-2) chance that the child will be a carrier of the disorder—just like the carrier parents. If only one parent is a carrier, there is a 50% (1-in-2) chance that the child will be a carrier of the disorder.
Who should be tested first? Male or female?
This is flexible. However, in the cases where there is no family history of genetic disease, testing the female first is recommended due to the assessment of X-linked disorders (as male only have one X chromosome, they already be impacted if they are carrying such variants).
What should I do if my partner and I both are positive for a condition?
- If you’re planning a pregnancy, you can consider In Vitro Fertilization (IVF). During the IVF process, physician will select embryos free of genetic problems through Ultra PGD/ PGT-A to implant. You can also consider other options such as implant donor’s egg or sperm which is not a carrier for the same condition.
- If you’re already pregnant, you can do a diagnostic test such as amniocentesis to determine if the inherited disease was passed on to your child. Discuss with your physician for the follow up treatment.
Should I have carrier screening if I am using donor eggs/sperm?
Yes. Carrier screening could help you to check whether you are the carrier of the same disease with donor, especially from an anonymous donor.