Lecture 8 - complex diseases

Question 1

digenic inheritance:
in retinitis pigmentosa, ____ at both genes is sufficient to cross a threshold of cell damage–>_____ death and loss of ____

Answer 1

heterozygosity;
photoreceptor;
vision

looks autosomal dominant but really 2 genes

Question 2

equation for relative risk ratio:

Answer 2

(prevalence of disease in relatives of affected person) / (prevalence of disease in general population)

Question 3

relative risk ratio:
a value of ____ indicates that a relative is not more likely to develop the disease than is any individual of the population;

a value greater than ____ indicates that a relative is more likely to develop the disease than another individual in the population

Answer 3

1, 1

Question 4

____ is a measure of the contribution of genetic factors to a trait or disease. ranges from ___ to ___

Answer 4

heritability;

0 to 1

Question 5

heritability:
if close to 0, trait is chiefly ____;
if close to 1, trait is chiefly ____

Answer 5

enviornmental;

genetic

Question 6

which would typically have a higher relative risk ratio, monozygotic twins or siblings?

Answer 6

the twins

Question 7

the _____ ___ ____ model hypothesizes that only individuals who have inherited a sufficient number of susceptibility alleles at various genes will develop the disease

Answer 7

multifactorial liability threshold

Question 8

cousins, great grandparents and half-neices are example of ___ degree relations. they share ___ genes with you

Answer 8

3rd;

1/8

Question 9

uncles, neices, grandparents, and grandchildren are examples of ___ degree relatives. they share ___ genes with you

Answer 9

2nd;

1/4

Question 10

if there is more than 1 affected individual in a pedigree, the ___ ____ increases. ie higher levels of susceptibility alleles

Answer 10

recurrence risk

mild forms of disease = smaller number susceptibility alleles

Question 11

pyloric stenosis:
5 times more common in ____;

affected ____ are at higher risk to have affected children

Answer 11

males;

females

Question 12

association studies are more powerful than linkage for finding variants with ___ effects that contribute to ___ traits

Answer 12

small;

complex

Question 13

alzheimer’s disease (AD):

early onset = ___ genetics

Answer 13

mendelian;

Question 14

AD (normal onset):

at least one ___ ___ allele causes 2-3x increased risk of getting it. 2 alleles = earlier onset

Answer 14

ApoE E4

predisposes, doesn’t predestine