Lecture 23 - pharmacogenomics

Question 1

Single nucleotide polymorphism

Answer 1

Single nucleotide polymorphisms are the most common type of genetic variation among people. Each SNP represents a difference in a single DNA building block, called a nucleotide.
to be classified as SNP - variant has to be found in at least 1% of the population

Question 2

phase 1 drug metabolism

Answer 2

mostly oxidation reactions to make water soluble intermediate with reactive handle

Question 3

phase 2 drug metabolism

Answer 3

conjugation reactions in which a transferase adds a chem group and creates excretable product

Question 4

pharmacogenomics

Answer 4

study of how genes affect a person’s response to drugs

Question 5

cytochrome p450 enzymes

Answer 5

catalyse most of phase 1 reactions
monooxygenase enzymes. use molecular oxygen and hydroxyl group to their target. the other oxygen from molecular mO2 reduced to water
enzymes use NADPH as their source of reducing power
55 genes encode related enzymes with different drug targets - group of genes that affect phase 1 metabolism

Question 6

genetic factors affecting sensitivity to warfarin

Answer 6

CYP2C9 - metabolises and inactivates warfarin
VKORC1 - encodes warfarin target

Question 7

CYP2C9

Answer 7

metabolises and inactivated warfarin. 2 common alleles reduce cyp2c9 enzyme activity. individuals with 1 or 2 of these alleles effectively have higher dose of warfarin if started on standard doese