Prenatal Genetics & Reproductive Options Flashcards

Carrier screening for spinal muscular atrophy (SMA) is recommended for:

Answer: All individuals of reproductive age regardless of ethnicity

Current ACOG guidelines recommend expanded carrier screening, including SMA, for all individuals of reproductive age due to pan-ethnic prevalence.

When both members of a couple are carriers for an autosomal recessive condition, the recurrence risk with each pregnancy is:

Answer: 25%

When both parents are carriers for an autosomal recessive condition, each pregnancy has a 25% chance of being affected.

A nuchal translucency (NT) measurement of ≥3.5 mm at 11–14 weeks is associated with increased risk for:

Answer: Chromosomal abnormalities and structural defects including cardiac anomalies

An increased NT is associated with a broad spectrum of chromosomal aneuploidies, structural anomalies, and genetic syndromes.

Preimplantation genetic testing for monogenic conditions (PGT-M) requires which INITIAL step?

Answer: Identifying the specific familial pathogenic variant through proband testing

PGT-M requires knowledge of the exact familial variant so the laboratory can design a specific probe or analysis strategy for the embryo.

A pregnant patient is found to have a fetal ultrasound showing an isolated echogenic bowel. This finding is associated with increased risk for which genetic condition?

Answer: Cystic fibrosis

Echogenic bowel is a soft marker associated with cystic fibrosis, as swallowed meconium in an affected fetus can appear echogenic on ultrasound.

When counseling a couple for whom one partner is a carrier of an X-linked recessive condition, which reproductive outcome is CORRECT?

Answer: 50% of sons will be affected and 50% of daughters will be carriers

For X-linked recessive conditions, carrier mothers pass the variant to 50% of sons (who are affected) and 50% of daughters (who are carriers).