Gene-Environment Interaction

Question 1

Malignant Hypertension - Strong contractions and Heat production by Sk.Muscles
What evokes the response?What is the mutation?

Answer 1

Anesthetics causes the RyR that is mutated to elevated the Ca in the cells

Question 2

Acute Intermittent porphyria - What does the Accumulation of Porphyrin cause? What is the trigger from outside the body?

Answer 2

Steroids, drugs, alcohol and starvation (dietary factors) will invoke the convolutions and hallucination.

Question 3

Variegate Porphyria - What is the invoking trigger? What is the outcome?

Answer 3

Light sensitivity and hallucinations are triggered by dietary factors.

Question 4

Minor allele frequency (MAF):

Answer 4

Minor allele frequency (MAF): the frequency at which the less (second most) common allele occurs in a given population. By definition it is < 0.5 (5%). If the MAF of an SNP is >5%, then it is called frequent, if between 0.5-5%, it is low, if it is below 0.5%, it is rare.

Question 5

High penetrant variations:

What is the corresponding Environmental Factor/Phenotype for Xeroderma pigmentosum/DNA repair?

Answer 5

UV light/skin cancer

Question 6

High penetrant variations:

What is the corresponding Environmental Factor/Phenotype for Phenylketonuria/PAH?

Answer 6

Phenylalanine/mental disorders

Question 7

High penetrant variations:

What is the corresponding Environmental Factor/Phenotype for Familial hypercholesterolemia/LDLR?

Answer 7

Cholesterol/atherosclerosis

Question 8

What are High penetrant variations?

Answer 8

Trait it produces will almost always be apparent in an individual carrying the allele. The variation significantly influences the function of a gene or its products.

Question 9

Low penetrant variations

Answer 9

Only sometimes produce perceptible phenotype. The variation does not influence significantly the
function of the gene or its products, or the intact gene is not essential for the normal phenotype. But in interactions with other variations or environmental factors its effect may be apparent.

Question 10

Low penetrant variations:

what is the Environmental Factor/Phenotype for Alpha 1-antitrypsin deficiency - SERPINA1 gene?

Answer 10

Emphysema from smoking

Question 11

Low penetrant variations:

what is the Environmental Factor/Phenotype for -Factor V Leiden, F5 gene?

Answer 11

Oral contraceptives, long physical inactivity (air travel), pregnancy increase the risk for development of DVT.

Question 12

h2 =

Heritability

Answer 12

h2 = additive genetic variance (VA)/ phenotypic variance (VP)

Question 13

Heritability ranges from 0 to 1. traits with no genetic variation have a heritability of:

Answer 13

0

Question 14

Since heritability is a function of the environment (VE),
it is a context dependent measure.
It is influenced by both:

Answer 14

− The environment that organisms are raised in

− The environment that they are measured in

Question 15

What is the Hardy Weinberg Principle?

Answer 15

For a rare allele, there are many more heterozygotes than there are homozygotes. (Based on mathematical analysis)

Question 16

Hardy Weinberg Equation is:
p^2 + 2pq + q^2 = 1.00 (100% of population)
What each of these elements mean?

Answer 16

p^2 = All the individuals that are homozygous dominant
q^2= All the individuals that are homozygous recessive
2pq = All heterozygotes

Question 17

Genotype # of Individuals
MM 1787
MN 3039
NN 1303

What is the genotypic frequency for heterozygotes?

Answer 17

MN = 3039/6129 = 50%

Question 18

Genotype # of Individuals
MM 1787
MN 3039
NN 1303

What is the genotypic frequency for Homozygous Dominants (MM)?

Answer 18

MM = 1787/6129 = 29%

Question 19

Genotype # of Individuals
MM 1787
MN 3039
NN 1303

What is the genotypic frequency for Homozygous Recessive (NN)?

Answer 19

NN = 1303/6129 = 21%

Question 20

What are the five elements that are disturbing the Hardy Weinberg equilibrium?

Answer 20

Disruption of Genetic Equilibrium
•Mutation
•Migration
•Genetic Drift
•Non random Mating
•Natural Selection

Question 21

Bottleneck effect

Answer 21

occurs when the numbers of individuals in a larger population are drastically reduced by a disaster. By chance, some alleles may be overrepresented and others underrepresented among the survivors.

Question 22

h2 = Va / Vp =
Since heritability is a function of the environment (Ve)
it is a context dependent measure. How? Complete the equation -

Answer 22

h2 = Va / Vp = Va / (Vg + Ve)

Question 23

What is Metagenomics?

Answer 23

It is the study of metagenome: genetic material recovered from environmental samples. (Like microbiome)