Question 1

Which of the following best describes a Single Nucleotide Polymorphism (SNP)?

Accepted Answer

A single base change in the DNA sequence that is present in at least 1% of the population.

Question 2

A patient is found to have the CYP2D6*1x4 genotype. What does this notation indicate?

Accepted Answer

The patient has four copies of the wild-type CYP2D6*1 allele.

Question 3

Which of the following genetic variations is most likely to cause a frameshift mutation?

Accepted Answer

An insertion of two nucleotides in a coding region

Question 4

In the context of pharmacogenomics, what does the 'star' (*) nomenclature system primarily classify?

Accepted Answer

Specific alleles of pharmacogenes based on their sequence variations

Question 5

A genetic test result shows a patient is homozygous for the CYP2C9*2 allele. What is the most likely implication?

Accepted Answer

The patient has two non-functional alleles and may have impaired drug metabolism.

Question 6

Which of the following best defines a haplotype?

Accepted Answer

A combination of alleles on the same homologous chromosome inherited together

Question 7

A patient with a duplication of the CYP2D6 gene (CYP2D6*1x4) is prescribed codeine. What is the most likely clinical consequence?

Accepted Answer

The patient will metabolize codeine more rapidly, increasing the risk of toxicity.

Question 8

Which of the following statements about alleles and variants is correct?

Accepted Answer

Variants is a broader term than alleles, encompassing all sequence differences.

Question 9

If a genetic variant is denoted as 3829G\u003eA, what does this mean?

Accepted Answer

At position 3829, guanine (G) has been replaced by adenine (A).

Question 10

Which of the following is true regarding copy number variations (CNVs)?

Accepted Answer

CNVs can lead to increased or decreased gene dosage, affecting protein levels.

Question 11

A patient is heterozygous for a gene, carrying one wild-type allele and one mutant allele. Which term best describes this genetic state?

Accepted Answer

Heterozygous

Question 12

Which of the following best describes the difference between SNPs and SNVs?

Accepted Answer

SNPs are a subset of SNVs that are present in at least 1% of the population.

Question 13

Which of the following would most likely result from an indel that is not a multiple of three base pairs?

Accepted Answer

A frameshift mutation

Question 14

A researcher identifies a new allele of the CYP2C9 gene that produces a non-functional enzyme. According to star nomenclature, how would this new allele likely be named?

Accepted Answer

CYP2C9*3

Question 15

Which of the following best describes the term 'wild type' in genetics?

Accepted Answer

The most common genotype and phenotype in a population.

Question 16

A patient’s genotype is reported as rs28371732. What does the 'rs' prefix indicate?

Accepted Answer

It is a reference to a specific SNP in a public database.

Question 17

Which of the following scenarios best illustrates the clinical impact of a copy number variation (CNV) in pharmacogenomics?

Accepted Answer

A patient with multiple copies of a drug-metabolizing enzyme gene, leading to increased drug metabolism.

Question 18

Which of the following is the correct formula for determining the number of possible genotypes for a gene with $$n$$ different alleles?

Accepted Answer

$$\frac{n(n+1)}{2}$$

Question 19

If a gene has three known alleles (A, B, and C), how many unique genotypes are possible in a diploid organism?

Accepted Answer

6 (calculated as $$\frac{3(3+1)}{2} = 6)$$

Question 20

Which of the following best explains why indels that are not multiples of three base pairs are more likely to have severe effects on protein function?

Accepted Answer

They cause a frameshift, altering the reading frame of the gene.

Genetic Variations and Nomenclature: Foundations for Pharmacogenomics

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