Preconception carrier screening  is screening that you can have before becoming pregnant. It helps you predict  your chances of having a child with a genetic disorder.

A carrier is an individual who has  no symptoms ( or mild symptoms) of a disorder and can pass the gene of the disorder to his/her child.

This screening can be done before or during pregnancy.  If it is done before pregnancy, you have a broader range of options and more time to make decisions.

The screening is available for a limited number of diseases such as

• sickle cell disease
• cystic fibrosis
• fragile X syndrome
• Tay-Sachs disease

How is preconception carrier screening done ?

It involves testing a sample of blood or saliva. The sample is sent to the lab for testing. The sample is sent to the lab for testing. The partner who is most likely to have the defective gene is tested first. If the results  show that the first partner is not a carrier , additional tests need to be done. If the test shows that the first partner is a carrier, the other is also tested.

Who should consider preconception carrier screening ?

Your health care provider  or genetic counselor can help you find out if you are at increased risk of passing a genetic disorder on by reviewing your family history. He will ask you certain questions about your health and your family’s health. You are at increased risk if :

• you have a genetic disorder
• you already have a child with a genetic disorder
• you have a family history of a genetic disorder
• you belong to an ethnic group that has a high rate of carriers of a certain genetic disorder

People of certain  ethnic groups are at increased risk of passing on a particular genetic disorder.  As a result , carrier screening is offered to  certain groups as follows :

• non hispanic white individual should be offered cystic fibrosis carrier screening
• people  of Eastern European Jewish descent (Ashkenazi Jews) should be offered screening for Tay–Sachs disease, Canavan disease, familial dysautonomia, and cystic fibrosis
• people of African, Mediterranean, and Southeast Asian heritage should be offered screening for thalassemias and sickle cell disease

What does the results of carrier screening mean ?

The results will be used to calculate your chances of having a child with genetic disorders . If both parents are carriers, there is a 25% chance that the child will have the abnormal gene from each parents and have the disorder. There is a 50% chance that the child will be a carrier. If one parent is a carrier, there is a 50% chance that the child will be a carrier of the disorder and a 0% chance that he will have the disorder.

You should note that you can get false positive and false negative results.  A false positive result  means a person  tests positive for being a carrier but does not actually have the gene. A false negative result means a person  test negative for the being a carrier but actually does have the gene. These screening can be wrong so it is possible to have a child with a genetic disorder even though you and your partner’s results came back negative.

What do i do if I’m a carrier ?

If you learn that both you and your partner  are carriers of a genetic condition, you have several options. You may chose  to proceed with becoming pregnant with the option  of considering prenatal diagnosis. You can also chose in vitro fertilization with donor egg and sperm to achieve pregnancy.Preimplantation genetic diagnosis can be used with this option. You also may choose not to become pregnant.

What is the Genetic Information Nondiscrimination Act (GINA)?

It is a law that makes it illegal  for health insurers to require genetic results or use results to make decisions about coverage , rates and preexisting conditions. It is prohibited for employers to use genetic information for hiring, firing or making any other decisions about a person’s employment .