Prenatal Genetic Testing and Screening: A Focused Review

Area of Science:

• Neurology
• Genetics
• Obstetrics

Background:

• Pediatric neurologists are increasingly involved in prenatal consultations due to advancements in prenatal testing.
• Understanding the nuances of prenatal tests is essential for effective family counseling during the gestational period.

Purpose of the Study:

• To differentiate between prenatal screening and diagnostic tests.
• To emphasize the importance of understanding the strengths, limitations, and predictive values of various prenatal tests.
• To highlight the necessity of comprehensive pretest and post-test counseling.

Main Methods:

• Review and categorization of prenatal testing methods into screening and diagnostic categories.
• Discussion of the characteristics, risks, and benefits associated with each type of testing.
• Emphasis on the role of predictive values in interpreting screening test results.

Main Results:

• Screening tests are non-invasive with no increased miscarriage risk, while diagnostic tests (chorionic villus sampling, amniocentesis) are invasive and carry miscarriage risks.
• Diagnostic tests encompass biochemical markers, enzyme testing, karyotype, microarray, whole exome sequencing, and whole genome sequencing.
• Effective counseling requires discussing potential unexpected findings and the patient's right to decline testing.

Conclusions:

• Pediatric neurologists require a thorough understanding of prenatal testing to counsel families effectively.
• Distinguishing between screening and diagnostic tests and interpreting results within clinical context using predictive values is imperative.
• Informed decision-making hinges on comprehensive counseling regarding the strengths, limitations, and risks of all prenatal diagnostic procedures.