What Is Carrier Screening?
Carrier screening is a genetic test used to determine if a healthy person is a carrier of a recessive genetic disease. It provides life-lasting information about an individual's reproductive risk and their chances of having a child with a genetic disease.
What is a recessive genetic disease?
A recessive genetic disease is caused when a mutation is present on both genes of a pair (one gene inherited from the mother and the other from the father).
Most people can be carriers of a disease-causing change without knowing it.
If both partners are carriers, they have a 25% risk of having an affected child with a recessive genetic disease and a 50% that the child will be a carrier like the parents.
Autosomal recessive disorder
In an autosomal disorder, if both parents are carriers for the same genetic diseases, there is a 25% chance of having an affected child in each pregnancy.
- There is a 1/4 (25%) chance that the child will be born with an autosomal recessive disorder. The child will have inherited two changed mutated genes, one from each parent
- There is a 1/2 (50%) chance that the child will be a carrier like the parents, but will not have any symptoms. The child will have inherited one normal gene and one mutated gene
- There is a 1/2 (50%) chance that the child will not inherit the defected gene with a change (mutation) from either parent. This child will not be a carrier and will not be affected by the disorder.
X-linked recessive disorder
In an X-linked recessive disorder, if the mother is a carrier, there is a 25% chance that she will have an affected male child in each pregnancy.
- There is a 1/2 (50%) chance that the child is a male or female who is a healthy with a normal copy of a particular gene
- There is a 1/4 (25%) chance that it is a healthy carrier female child or a mildly affected female child
- There is a 1/4 (25%) chance that it is an affected male with only one mutated copy of the gene
What are the benefits of carrier screening?
Carrier screening can help partners make informed decisions and choices regarding family planning that are consistent with their values. It can allow couples to:
- Plan their pregnancy via pre-implantation genetic diagnosis (PGD)
- Pursue alternate options such as using a sperm or egg donor or adoption
- Have prenatal diagnosis during pregnancy
- Avail specialist care during pregnancy and delivery if necessary
- Prepare for management and if available, treatment of anaffected child
CentoScreen® testing options
CENTOGENE offers CentoScreen®, the most complete genetic screening test with ≥99% coverage of 332 genes, providing couples and physicians with the highest confidence in test results.
What does carrier screening find?
The screening panel includes a large list of inherited conditions including:
- Fragile x syndrome
- Spinal muscular atrophy
- Cystic fibrosis
The ideal time for screening is pre-pregnancy. However, individuals can be tested before, during, and after pregnancy. When performed prior to conception, this test provides individuals with a broader range of options.
Please contact your physician or genetic counselor. If they have questions they can always reach out to our medical experts at CENTOGENE at customer.support(at)centogene(dot)com for more detailed information.
CentoScreen® is a clinical test that has to be ordered by a physician. You can contact your physician or genetic counselor to discuss if CentoScreen® is appropriate for you and your partner. After your pre-test genetic counseling session, your physician will order the test and send the sample to Centogene for testing with your consent.
CENTOGENE uses an innovative collection method called CentoCard®, a filter card used to collect samples for testing. DNA can be obtained for testing from a few drops of blood spotted on one CentoCard®.
CentoCards® can be ordered by your physician online at no additional charge.
Alternatively, your physician can also send us 1ml of whole blood in an EDTA tube.
Your test results will be sent to your physician in 15 business days after sample receipt.
Once the results are received, your physician will discuss the results with you and your partner and provide you with information on any further follow-up if necessary.
CentoScreen® carrier testing only needs to be done once in your lifetime for you and your partner. However if you are identified as a carrier and have a new partner, carrier testing is recommended for your new partner.
If you are identified as a carrier of an autosomal recessive disorder, the next step is to determine your partner’s carrier status. If both you and your partner are determined to be carriers for the same genetic condition, then there is a 25% (1 in 4) chance in every pregnancy that the child will be born with an autosomal recessive disorder.
If the female partner is identified as a carrier of an X-linked recessive disorder, there is a 50% chance that it is an affected male child with only one mutated copy of the gene.
In cases where the test results identify both you and your partner as carriers for a genetic disease, it is important to know that you have many options you should discuss with your physician or genetic counselor.
If needed, further prenatal testing for the particular genetic disease can be performed at CENTOGENE in a short turnaround time, allowing you enough time to plan further steps, together with your physician and genetic counselor.
Who should consider CentoScreen®?
Carrier screening done before pregnancy will give you a broader range of options consistent with your values and offer you more time to make an informed decision. CentoScreen® is suitable for individuals or couples considering a pregnancy or in early pregnancy and for individuals or couples with the following backgrounds:
Pretest genetic counseling with your doctor
Doctor draws blood and ships sample
Sample arrives at the lab and DNA is extracted and analyzed
Test report is created and shared with your doctor