pharmacogenetics (11)

Question 1

what are the 4 most common categories of personal medicine

Answer 1

1. drug therapy
2. idiopathic disease
3. cancer diagnosis, prognosis, treatment
4. prenatal testing & new born screening

Question 2

define pharmacogenetics

Answer 2

this relates heritable variation to inter-individual variation in drug response

Question 3

what word is the following describing:
study of mechanisms of absorption & distribution of an administered drug, the rate at which a drug action begins and the duration of the effect

Answer 3

pharmacokinetics

Question 4

tell me about the the normal (extensive) group for targeted gene therapy

Answer 4

group has the presence of 2 functional alleles that work in the expected fashion
this is the group that drug companies target

Question 5

tell me about the the “poor metabolizer” group for targeted gene therapy

Answer 5

A poor metabolizer has no functional allele for this gene and has difficulty converting the drugs to their usable form. There may be very low level of enzyme activity and in that case the conversion process would be very slow. This could result in the accumulation of chemicals in the body which may be toxic and these individuals would require a lower dose of the drug

Question 6

tell me about the the ultra metabolizer group for targeted gene therapy

Answer 6

has duplicate copies of the functional alleles and generally degrades the drug so rapidly that is eliminated before therapeutic levels can be reached. Higher doses of the drugs would be needed here

Question 7

how does warfarin work?

Answer 7

Works by inhibiting the enzyme: epoxide redutase (aka vitK reducatase) resulting in the inhibition of vit K metabolism

Question 8

what two drugs are involved in the metabolism of warfarin?

Answer 8

Cytochrome P450- CYP2C9

Vit K epoxide reductase complex 1 (VKORC1)

Question 9

what race tends to be the least sensitive to warfarin? genetically why?

Answer 9

• Least sensitive to the drug due to homozygote VKORC1 is common in blacks

Question 10

what race tends to be the most sensitive to warfarin? genetically why?

Answer 10

Most sensitive to the drug due to the non-homozygote VKORC1 is common in Asians

Question 11

what are some hesitations with making a genome wide microarray scan?

Answer 11

What are some concerns: what gene will be included in the chip? Who decides? If an individual doesn’t want to know this info, can be opt out of the test? What is the psychological burden of knowing your disease risk throughout life

Question 12

what can be assumed If regions of homozygosity exceed 5% of the genome? it is likely that is due to identity by decent (inbred populations etc)

Answer 12

it is likely that is due to identity by decent (inbred populations etc)

Question 13

list some key provisions in the GINA law

Answer 13

• Prohibits insurers or health plan administrators from using gentic info in decisions about coverage or rates
• Prohibits employers from using genetic info for hiring, firing or promotions

Question 14

list some things that the GINA law does not cover =(

Answer 14

• Cover life insurance, disability of long term care insurance
• Does not apply to businesses with fewer than 15 employees
• Does not prohibit a health insurer from determining eligibility or premium rates based on the presence of a disease

Question 15

what are 3 types of population screening

Answer 15

1. prenatal screening
2. new born screening
3. carrier screening

Question 16

what are 4 key factors in carrier screening?

Answer 16

• 1. The mutation must be in a reasonably high frequency in the population
• 2. The test is suitable for mass screening
• 3. Genetic counseling available to explain the results to the families
• 4. Prenatal testing available so that when carrier couples are identified, it is possible to determine when a pregnancy will result in an affected child