Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

IMS > GENETICS OF COMPLEX DISEASES > Flashcards

GENETICS OF COMPLEX DISEASES Flashcards

1
Q

how common are single gene mutations in disease?

A

rare

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are single gene mutations in disease?

A

Mutations in a gene Dominant/recessive pedigree patterns

Structural proteins, enzymes, receptors, TF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

how common are Multifactorial/Complex?

A

common

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

how many genes are affected in Multifactorial/Complex?

A

> 1 gene affected, gene variants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

how common are Chromosomal changes?

A

common

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

how many genes are affected Chromosomal changes?

A

100’s of genes affected, e.g. gain/loss of chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how common do Environmental factors affect disease?

A

very common

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

give examples of environmental factors that effect disease?

A

Includes viral/bacterial infections, affect disease penetrance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is multifactorial inheritance?

A

The inheritance and expression of a phenotype being determined by the cumulative action of multiple genes at multiple loci.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what effect do the genes have in multifactorial inheritance?

A

Each gene contributes a small amount to a final phenotype that is also significantly influenced by environmental factors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is the effect of each gene contributing to the phenotype in multifactorial inheritance?

A

As a result these multiple genes are not viewed as being dominant or recessive to each other.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

how are the genes arranged in multifactorial inheritance?

A

These multiple genes do segregate in a Mendelian manner, but the phenotype does not.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are monogenic diseases?

A

Have a single strong highly penetrant phenotype

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how common are monogenic diseases?

A

very rare

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are modifiers?

A

Other genes that affect phenotype severity (e.g. regulate expression of the disease allele) but the primary gene dominates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how common are polygenic diseases?

A

very common

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are polygenic diseases?

A

Have lower penetrant phenotypes
Not dominated by one gene though a genetic locus could have a predominant effect (e.g. BRCA1/2 genes in breast/ovarian cancers)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what effect does environmental contribution have on polygenic diseases?

A

reduces penetrance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what are pedigrees?

A

more complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what is penetrance?

A

the fraction of cases carrying a given gene that manifests in a specified phenotype

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what are the 2 factors that cause any trait?

A

genetics

environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

give examples of polygenic complex diseases?

A

Obesity, Schizophrenia, Alzheimer’s, Asthma, Multiple sclerosis, Autism, Cancer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Why study genetics of multifactorial disease?

A

Identify individuals with an increased risk of disease
Understanding may identify targets for better therapy
Untangle complexity of gene-environment interactions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

why is complex inheritance the underlying factor for most common human diseases?

A

Multifaceted interactions of genotypes at multiple loci

Environmental factors that trigger, accelerate or worsen disease development

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what is polygenic inheritance?

A

Traits are usually quantified by measurement

>= 2 genes contribute to the phenotype

26
Q

does phenotypic variation in polygenic inheritance vary?

A

yes across a wide range

27
Q

how is polygenic inheritance best analysed?

A

in populations rather than individuals

28
Q

what does the interaction of genes with the environment produce?

A

a wide range of phenotypes

29
Q

give an example of polygenic inheritance

A

adult male height

30
Q

what are the 2 methods to study multifactorial traits?

A

Threshold model

Recurrence risk

31
Q

what is the threshold model?

A

Frequency of disorder among relatives is compared with the frequency of the disorder in the general population

32
Q

what is the recurrence risk?

A

Estimates the risk that the disease will recur

33
Q

what is the liability threshold?

A

Measure of the disease state of an individual
When alleles push the distribution towards the liability threshold they are termed ‘risk alleles’ or susceptibility alleles

34
Q

are all alleles additive?

A

not all of them

some are dominant, epistatic (=modifier genes), protective

35
Q

what is heritability?

A

the proportion of disease variation due to genetic variation

36
Q

what is monozygotic twins?

A

Single fertilization

Genetically identical

37
Q

what is dizygotic twins?

A

Independent fertilization events

Share approximately half their genes

38
Q

what is concordance?

A

probability (%) that twins (identical or non-identical) will both have the disease, given that one of the pair has the disease

39
Q

how do you estimate heritability?

A

Difference between the % concordance in dizygotic twins versus monozygotic twins

40
Q

how do you estimate the genetic, shared environment and non-shared environment contributions?

A

By looking at the concordance and discordance between mono- and dizygotic twins

41
Q

how is familial breast cancer caused?

A

Known genes (e.g. BRCA1&2) involved in familial breast cancer account for <30% of the familial risk

42
Q

what is autism?

A

characterized by great difficulty in communicating, forming relationships and in using language and abstract concepts
Known to be strongly influenced by genetics

43
Q

what is an allele?

A

one of a number of alternative forms of the same gene

44
Q

how are disorders inherited?

A

Studies have shown that an individuals risk of inheriting certain disorders correlates to the relatedness of affected family members (e.g. schizophrenia)

45
Q

what are Single Nucleotide Polymorphisms

(SNPs)?

A

DNA sequence variations that occur when a single nucleotide in the genome sequence is altered at the same genetic location between different chromosomes

46
Q

how are variations considered a SNP?

A

variation must occur in >= 1% of the population

47
Q

what do SNPs act as?

A

While most have no effect on protein function, it is believed they can act as biological markers, helping us identify genes associated with disease

48
Q

what do SNPs help to understand?

A

widely differing susceptibilities to complex yet common diseases

49
Q

what are SNPs used as?

A

to map haplotypes

50
Q

what are haplocytes?

A

disease-linked genomic loci that are physically linked on a chromosome and segregate together

51
Q

what are GWAS?

A

genome-wide association study

52
Q

how many genes are involved in chromosomal disorders?

A

thousands

53
Q

what is aneuploidy?

A

presence of an abnormal number of chromosomes in a cell

Humans should have 46 chromosomes

54
Q

give examples of aneuploidy affecting sex chromosomes?

A 
Triple-X syndrome (47,XXX) Klinefelter syndrome (47,XXY)  XYY syndrome (47,XYY) 
Turner syndrome (45,X0)
55
Q

why is aneuploidy nearly always deleterious?

A

because of genetic imbalance

56
Q

give examples of autosomal chromosomes?

A

Trisomy 21, Down syndrome
Trisomy 18, Edward syndrome
Trisomy 13, Patau syndrome

57
Q

what is DiGeorge Syndrome?

A

Deletion of band 11.2 on long arm of chr 22

58
Q

what are the symptoms of DiGeorge Syndrome?

A

Congenital cardiac defects, facial dysmorphia, thymic aplasia, cleft palate, hypocalcemia, learning disabilities, T-cell immunodeficiency

59
Q

what causes down’s syndrome?

A

Meiotic non-disjunction

60
Q

what is non-disjunction?

A

failure of chromatids to separate into 2 chromosomes

61
Q

what effect does non-disjunction have on age?

A

increases with maternal age

IMS (52 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions