Multifactorial Disorders Flashcards Preview

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Flashcards in Multifactorial Disorders Deck (41):
1

chromsomal and genomic disorders affect what percentage of the poplaution

0.38%

2

single gene disorders affect what percentage of the popluation

2%

3

disorders with multifactorial inheritance affect what percentage of the population

60%

4

the more genes are involved ...

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

5

higher number of genes involved...

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

6

what do we assume during the analysis of quantitiative traites

many genes are invovled with the development of disease
alleles can be contriubting or noncontributing to disaes phenotupes

7

liability distribtuion

bell curve of phenotype distrubtion

8

threshold of liabity

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

9

recurrene risk is higher than what in multifactorial disorders

occurrence risk

10

is pyloric stenosis imore common in men or women

males

11

why does pyloric stenosis affect more males

they need fewer contributing alleles to exxpress the disease

12

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

female

13

falconer's formula (twins)

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

14

concordant trait

triat shared by both twins

15

disease with a signifcant genetic compoentn will show waht

high concordance rate in MZ twins than DZ twins

16

MZ twin

identical

17

linkage analysis

mapps an unknown number o fcontributin glici

18

model free linkage analysis

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

19

why is model free linkage insensitive

needs a very large sample size

20

why is model free linkage imprecise

maps the contributing allele to a very alrge chormsomal region

21

incidence

how many new cases are recorded in a given time

22

prevalence

what proportion of the population has the disease

23

relative risk ratio

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

24

what is the risk of multifactorial birth defec ting eneral population

0.5

25

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

0.7 -2%

26

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

3-4%

27

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

5-8%

28

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

9-12%

29

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

20-30

30

disease association of allele

how the allele in question influecnes the risk for the disorder

31

relative risk

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

32

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

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

33

where is MHC locus found

chromsome 6

34

fucntion of MHC class I and II

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

35

HLA gene charactersiti

polymorphic

36

how are HLA haplotypes expressed

codominat manner

37

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

25%

38

what types of disease does HLA haplotypes tend to favor

immuen system disease

39

what is unqieua bout DR-DQ haplotypes and T1D

some are susceptibiliy alleles and some are protective alleles

40

HLA-B haplotypes determine risk for waht

spondyloarthropathy

41

HLA-C haplotypes predict risk for what

psoriatic arthritis