Jennifer Saucier, Board-Certified Genetic Counselor and Senior Director of Clinical Genetic Services at Natera, discusses the difference between screening and diagnostic testing.
As Ms. Saucier explains, screening tests are designed to determine the risk of a child being born with a condition whereas a diagnostic test determines whether the child has a condition. Therefore, it is recommended that an individual who receives a high-risk screening result also have a diagnostic test done when it is appropriate to definitively diagnose a condition. Ms. Saucier uses the analogy of airport security to describe screening tests – bags are screened for a potential threat but follow-up is necessary to confirm or deny the threat.
Some screening tests that are performed during pregnancy are under the umbrella of noninvasive prenatal testing (NIPT), which screens for certain genetic abnormalities by analyzing cfDNA circulating in a pregnant woman’s blood. Currently, NIPT is most often used to screen for chromosomal disorders caused by aneuploidy such as Down syndrome, trisomy 18, trisomy 13, and extra or missing copies of the sex chromosomes. Conditions caused by microdeletions such as 22q11.2 deletion syndrome may also be screened for using NIPT.
To learn more about genetic testing and rare genetic disorders, visit checkrare.com/diseases/congenital-and-genetic-conditions/