Pharmacogenetics

Question 1

Pharmacogenetics

Answer 1

Genetic factors that alter an individual’s drug response to a drug

• genetic polymorphisms
• less common genetic variants

Question 2

Genotype

Answer 2

An individual’s composition at the gene level, i.e. the specific genes they have

Question 3

Phenotype

Answer 3

An individual’s expression of their genotype

Question 4

Genetic polymorphism

Answer 4

Mendelian trait that exists in the population in at least two phenotypes neither of which is rare (i.e. at least one variant that represents greater than 1% of total pool)

Question 5

Single nucleotide polymorphism (SNP)

Answer 5

A change in one single base pair in the DNA sequence that differs from the “wild type” or predominant sequence

• these may or may not result in an altered phenotype

Question 6

Haplotype

Answer 6

Refers to closely linked genetic markers on a chromosome that tend to be inherited together

• often within a gene or closely linked genes

Question 7

Halotypes

Answer 7

Refers to a cluster of SNPs that occur together in an individual (and are of interest to a phenotype)

• useful for categorizing individuals to understand how clusters of SNPs can contribute ot phenotype
• multiple SNPs may be in a single gene (similar to haplotype) or multifactorial, multiple genes not necessarily inherited as a unit

Question 8

Autosomal co-dominance

Answer 8

Each allele contributes to phenotype

Question 9

Autosomal recessive

Answer 9

Wild-type allele has predominant effect; it takes two recessive alleles to see the effect

Question 10

Autosomal dominant

Answer 10

A single allele predominates over the presence of other possible alleles

Question 11

X-linked inheritance

Answer 11

Genes inherited on X chromosome; all males will express these traits (males are hemizygous)