CGC Prenatal Genetics & Reproductive Options 3

Question 1

The quad screen (maternal serum analytes) is a second-trimester screening test that includes which analytes?

Accepted Answer

AFP, hCG, unconjugated estriol, and inhibin A

Answer

AFP, hCG, PAPP-A, and inhibin A

Answer

AFP, hCG, PAPP-A, and NT

Answer

AFP, unconjugated estriol, PAPP-A, and inhibin A

Question 2

A patient is found to have a fetus with a de novo pathogenic variant identified on exome sequencing. 'De novo' means:

Accepted Answer

The variant arose newly in the fetus and is not present in either parent

Answer

The variant was inherited from the mother

Answer

The variant is of uncertain significance

Answer

The variant was inherited from the father

Question 3

Confined placental mosaicism (CPM) is a limitation unique to which prenatal diagnostic procedure?

Accepted Answer

Chorionic villus sampling (CVS)

Answer

Amniocentesis

Answer

Cell-free DNA screening

Answer

Fetal blood sampling

Question 4

A patient asks about the difference between a 'screen positive' and a 'diagnostic positive' result for Down syndrome. The counselor correctly explains that:

Accepted Answer

A screen positive indicates increased risk but requires diagnostic confirmation; a diagnostic positive confirms the diagnosis

Answer

Both terms mean the same thing clinically

Answer

A diagnostic positive is less reliable than a screen positive

Answer

Screen positives are used only for research purposes

Question 5

Chromosomal microarray analysis (CMA) in the prenatal setting has advantages over karyotype because it can detect:

Accepted Answer

Submicroscopic copy number variants (CNVs) not visible by standard karyotype

Answer

Only larger chromosomal deletions

Answer

Single-gene variants

Answer

Trinucleotide repeat expansions

Question 6

A patient presents at 14 weeks gestation after a CVS revealed trisomy 21 in the fetus. The genetic counselor should provide counseling that includes:

Accepted Answer

Balanced information about the condition, reproductive options, and support resources

Answer

Only information supporting continuation of the pregnancy

Answer

Only information about termination options

Answer

A referral to a developmental pediatrician without further discussion