Multifactorial Disorders

Question 1

chromsomal and genomic disorders affect what percentage of the poplaution

Answer 1

0.38%

Question 2

single gene disorders affect what percentage of the popluation

Answer 2

2%

Question 3

disorders with multifactorial inheritance affect what percentage of the population

Answer 3

60%

Question 4

the more genes are involved …

Answer 4

the lower the probabiliy of an offspring inheriting all or none of the contributing alleles

Question 5

higher number of genes involved…

Answer 5

lower the fraction of extreme phenotypes at the fringes of the bell curve

Question 6

what do we assume during the analysis of quantitiative traites

Answer 6

many genes are invovled with the development of disease

alleles can be contriubting or noncontributing to disaes phenotupes

Question 7

liability distribtuion

Answer 7

bell curve of phenotype distrubtion

Question 8

threshold of liabity

Answer 8

can be differnt for men and women
influenced by environment
once you pass this point you ge tthe disease

Question 9

recurrene risk is higher than what in multifactorial disorders

Answer 9

occurrence risk

Question 10

is pyloric stenosis imore common in men or women

Answer 10

males

Question 11

why does pyloric stenosis affect more males

Answer 11

they need fewer contributing alleles to exxpress the disease

Question 12

who has a higher risk of an affected sibling with pyloric stenosis, an affected male or female

Answer 12

female

Question 13

falconer’s formula (twins)

Answer 13

hertibility H2 = ( concordance MZ- concordance DZ) x 2

Question 14

concordant trait

Answer 14

triat shared by both twins

Question 15

disease with a signifcant genetic compoentn will show waht

Answer 15

high concordance rate in MZ twins than DZ twins

Question 16

MZ twin

Answer 16

identical

Question 17

linkage analysis

Answer 17

mapps an unknown number o fcontributin glici

Question 18

model free linkage analysis

Answer 18

insensitive and imprecise but doesn’t amke possible incorrect assupmtions about the number of genes inboled

Question 19

why is model free linkage insensitive

Answer 19

needs a very large sample size

Question 20

why is model free linkage imprecise

Answer 20

maps the contributing allele to a very alrge chormsomal region

Question 21

incidence

Answer 21

how many new cases are recorded in a given time

Question 22

prevalence

Answer 22

what proportion of the population has the disease

Question 23

relative risk ratio

Answer 23

prevalence of the diseas in r of affeccted person / precvalence in general population

Question 24

what is the risk of multifactorial birth defec ting eneral population

Answer 24

0.5

Question 25

what is the risk of multifactorial birth defect in 2nd degree relative

Answer 25

0.7 -2%

Question 26

what is the first of multifacotiral birth defect if 1sst degree relative is affected

Answer 26

3-4%

Question 27

what is the rist of multifactorial birth defect if 2 first degree relatives are affected

Answer 27

5-8%

Question 28

what is the risk of multifactorial birth defect if 3 first degree relatives are affected

Answer 28

9-12%

Question 29

what is the risk o fmultifacotiral birth defect if identifcal twin is affected

Answer 29

20-30

Question 30

disease association of allele

Answer 30

how the allele in question influecnes the risk for the disorder

Question 31

relative risk

Answer 31

percentage of people with the allele who develop the trait with the percentage of people without the allele who develope it

Question 32

4 charactersitcs of multifactorial disease tha tset them apart from single gene disorders

Answer 32

- don't follow mendelian patterns of inheritance - familial aggegration - incomplete penetrance - much more common amoung close relatives than less closely related

Question 33

where is MHC locus found

Answer 33

chromsome 6

Question 34

fucntion of MHC class I and II

Answer 34

encode cell surface proteins that play role in iniation of immuen resposne

Question 35

HLA gene charactersiti

Answer 35

polymorphic

Question 36

how are HLA haplotypes expressed

Answer 36

codominat manner

Question 37

if parent and child share 1 haplotype waht is the chance of 2 sibling expressing identical haplotypes

Answer 37

25%

Question 38

what types of disease does HLA haplotypes tend to favor

Answer 38

immuen system disease

Question 39

what is unqieua bout DR-DQ haplotypes and T1D

Answer 39

some are susceptibiliy alleles and some are protective alleles

Question 40

HLA-B haplotypes determine risk for waht

Answer 40

spondyloarthropathy

Question 41

HLA-C haplotypes predict risk for what

Answer 41

psoriatic arthritis