CGC Genomic Testing & Interpretation 2

Question 1

Which of the following is NOT a standard ACMG/AMP variant classification category?

Accepted Answer

Likely deleterious

Answer

The five ACMG/AMP tiers are pathogenic, likely pathogenic, VUS, likely benign, and benign.

Question 2

The ACMG/AMP criterion PVS1 applies to which type of variant?

Accepted Answer

A null variant in a gene where loss of function is a known disease mechanism

Answer

PVS1 is very strong evidence for nonsense, frameshift, canonical splice-site, or similar null variants in LOF-mechanism genes.

Question 3

A variant has an allele frequency of 8% in a large general population database. Which ACMG/AMP criterion is most applicable?

Accepted Answer

BA1, a stand-alone benign criterion

Answer

An allele frequency above 5% is considered stand-alone evidence for a benign classification.

Question 4

A missense variant is confirmed de novo in a child with a consistent phenotype, with maternity and paternity confirmed. What ACMG/AMP evidence does this support?

Accepted Answer

PS2, a strong pathogenic criterion

Answer

A confirmed de novo variant with a matching phenotype supports pathogenicity, with PS2 requiring confirmed parentage.

Question 5

A laboratory reclassifies a previously reported VUS as likely pathogenic. What is the most appropriate next step?

Accepted Answer

Issue an amended report to the ordering provider so the patient can be recontacted

Answer

Reclassifications that affect care should be communicated through an amended report so the provider can recontact the patient.

CGC - Certified Genetic Counselor Practice Test

CGC - Certified Genetic Counselor Practice Test

CGC Genomic Testing & Interpretation 2