Genetic disorders are conditions that develop when a child inherits either one or two (depending on the condition) copies of a specific gene mutation. Some genetic disorders need two copies of the same genetic mutation in order to develop. These conditions are called recessive disorders. Other genetic disorders only require one copy of the mutated gene to be inherited.
More and more, expecting parents and couples planning a pregnancy are interested in understanding the risk that their child may develop a genetic disorder. For this reason, scientists have developed genetic carrier screening technology that identifies individuals who are at risk of passing on a genetic mutation associated with recessive disorders to their children.
What Does a Positive Genetic Carrier Screening Result Mean?
A positive result of a genetic carrier screening test means that the individual tested is a genetic carrier. Individuals who are genetic carriers have inherited one mutated copy of a specific gene associated with a certain genetic disorder. While these individuals do not show signs or symptoms of the disorder, they are at risk of passing this abnormal gene on to their children if their partner is also a genetic carrier.
What is the Risk My Child Will Inherit a Genetic Disorder?
In the case of recessive disorders, since two copies of the mutated gene are needed in order for the condition to develop, both parents must test positive as genetic carriers in order for their child to have a risk of developing the condition.
However, this does not mean that their children will definitively develop the condition. Each time two individuals carrying the same genetic mutation have a child, the probabilities are:
- 25 percent chance that the child will develop the condition
- 50 percent chance the child will not develop the condition but will be a carrier
- 25 percent chance the child will not develop the condition and will not be a carrier
If only one person in the couple tests positive as a genetic carrier, then there is a zero percent risk that the child will develop the condition. However, the child has a 50 percent chance of being a carrier.
Making Important Healthcare Decisions For Your Child
Information obtained from genetic carrier screening tests can alert couples and their doctors to any additional measures that should be taken throughout pregnancy. For example, if two individuals expecting a baby are both carriers for cystic fibrosis, doctors will want to monitor the health of the baby more closely throughout the pregnancy. If there is suspicion that the baby has developed the condition, parents can choose to undergo prenatal testing in order to confirm the diagnosis. Having a diagnosis early on allows couples to plan necessary medical care for their child.
Want to Learn More About Genetic Carrier Screening?
If you are planning a pregnancy or are expecting a child and would like to learn more about genetic carrier screening and your carrier status, make an appointment to speak with a genetic counselor. Genetic counselors are healthcare professionals that are specially trained in medical genetics and counseling. These individuals provide information to couples who would like to know more about the risk that their child may be born with a genetic condition.
Sources:
http://www.mayoclinic.org/autosomal-recessive-inheritance-pattern/img-20007457
https://www.cff.org/What-is-CF/Testing/Carrier-Testing-for-CF/
https://www.babycenter.com/0_carrier-screening-for-inherited-genetic-disorders_1453030.bc
http://www.hopkinsmedicine.org/fertility/resources/genetic_screening.html
http://www.webmd.com/a-to-z-guides/tc/genetics-carrier-identification
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