Carrier screening tests may target various genetic disorders, including those caused by autosomal recessive, autosomal dominant, or X-linked inheritance patterns. Examples include cystic fibrosis, sickle cell anemia, Tay-Sachs disease, and hemophilia.
Carrier screening is particularly relevant for conditions that follow an autosomal recessive inheritance pattern. In these cases, both parents must be carriers for there to be an increased risk of the condition manifesting in their offspring.
Some carrier screening tests are recommended based on an individual’s ethnicity or specific populations with a higher carrier frequency for certain conditions. For example, individuals of Ashkenazi Jewish descent may be offered screening for conditions like Tay-Sachs disease and Gaucher disease.
Carrier screening can be done before conception to assess the risk of having a child with a particular genetic disorder. In some cases, carrier screening may also be offered during pregnancy through prenatal testing methods like chorionic villus sampling (CVS) or amniocentesis.
Genetic counseling is typically recommended before and after carrier screening. Genetic counselors help individuals understand the implications of carrier status, discuss the risk of having an affected child, and explore available options, such as preimplantation genetic testing or prenatal diagnosis.
Some carrier screening tests involve analyzing multiple genes associated with various genetic conditions simultaneously. These expanded carrier screening panels provide a broader assessment of carrier status for a range of disorders.
Carrier screening does not provide information about the health of the tested individual but focuses on the risk of passing on a genetic condition to their offspring. Additionally, carrier screening may not cover all possible genetic disorders, and negative results do not eliminate the risk of having a child with a genetic condition.