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Biochem V > Multifactorial Diseases > Flashcards

Flashcards in Multifactorial Diseases Deck (34):
1

What does the threshold of liability indicate/?

how many contributing alleles are required for a patient to be affected by a disease

2

What is a concordant trait?

a trait shared by both twins

3

What is a discordant trait?

a trait not shared by twins

4

What does high heritability indicate?

that a disease is mainly determined by genetic factors

5

What is incidence?

describes how many new cases are recorded in a given time

6

What is prevalence?

describes the proportion of the population that is affected by the disease at any given time

7

What are the most common genetic diseases?

multifactorial inheritance

8

How can one estimate the number of genes involved in a multifactorial disease?

shape of bell curve

9

Regarding a multifactorial disease, the higher number of genes involved does what to the shape of the bell curve?

lower the fraction of extreme phenotypes

10

What is a liability distribution?

shape of bell curve of phenotypes for multifactorial diseases

11

Why does the recurrence risk of a multifactorial disease increase with each diagnosis of a relative?

more disease contributing alleles likely present

12

Which sex is more likely affected by pyloric stenosis?

male

13

Which sex requires fewer contributing alleles to develop pyloric stenosis?

males

14

If a female develops pyloric stenosis, what does this mean for the number of contributing alleles she possesses?

she likely has a larger number

15

What is a concordant trait?

a trait shared by two twins

16

What is the term for a trait not shared by twins?

discordant

17

What is the equation for heritability?

(concordance MZ - concordance DZ)*2

18

What is incidence?

how many new cases are recorded in a given time divided by the size of the population

19

What is prevalence?

proportion of population that is affected at any given time

20

What is the equation for relative risk ratio?

prevalence of disease of relatives / prevalence of the disease in the general population

21

Do multifactorial diseases follow Mendelian inheritance?

No

22

Do multifactorial diseases show complete or incomplete penetrance?

incomplete

23

On what chrmosome is the MHC gene found?

chromosome 6

24

What are MHC class I and II genes involved in?

initiating immune response

25

How are HLA genes transmitted? Why is this?

as a whole unit

very little meiotic recombination

26

What is a compound heterozygote?

two mutant alleles are not identical

27

What is the genetic transmission of the HLA genes classified as?

haplotype

28

How are the HLA haplotypes expressed?

co-dominant

29

What is the percentage of MHC haplotypes shared by parent and child?

half

30

What are the changes of two siblings sharing identical haplotypes?

25%

31

In order to find an organ donor, what must one do?

match the HLA haplotypes

32

What haplotype affects T1D?

DR-DQ

33

What is HLA-B associated with?

Spondyloarthropathy

34

What is HLA-C associated with?

Psoriatic Arthritis