Genetic and epigenetic medicine Flashcards Preview

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Flashcards in Genetic and epigenetic medicine Deck (44)
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1
Q

what does genomic medicine discovery reseach assess?

A

genotype phenotype association

2
Q

human genome has how many bases?

A

3 million

3
Q

___% of the human genome is the same in all people

A

99.9

4
Q

what are the differences in DNA called between different people (the 0.1%)

A

polymorphisms

5
Q

what is the most common polymorphism?

A

single nucleotide polymorphism- involves only one base

6
Q

TF: single nucleotide polymorphisms have no effect on health

A

false
sometimes they have no effect but others they can lead to a change in function which increases your predisposition to a disease

7
Q

how can we assess which nucleotide polymorphisms cause disease?

A

by comparing the single nucleotide polymorphisms in health people with patients diagnosed with certain diseases

8
Q

what are the studies investigating the associations between disease and healthy polymorphisms?

A

genome wide association studies

9
Q

what happens in genome wide association studies?

A

compare DNA of 2 groups of similar people with and without the disease
single nucleoptide polymorphism arrays read their DNA, if one variant is more frequent in people with the disease that polymorphism is said to be associated with the disease

10
Q

what is functional genomics

A

investigation of large datasets produced by the genome aiming to determine the function of genes, RNA and proteins

tries to make sense iof the results of genomic association studies

want to find out the FUNCTIONS of the genes

11
Q

how does genomics differ from functional genomics?

A

functional genomics focuses on the dynamic aspects such as:
gene transcription
translation
protein protein interactions

as oppose to just genomic information such as sequence and structure

12
Q

what is comparative genomics?

what can this help us understand

A

aims to compare the genome sequence of different species

how genes are conserved through evolution and how they function

13
Q

what is the biobank

A

a collection of biological samples for referencing purposes

14
Q

BRCA1 and BRCA2 are what?

A

tumour suppressor genes which if mutated can lead to cancer

15
Q

what is pharmacogenomics?

A

how the cell responds to drug treatment

16
Q

what is pharmacogenetics

A

how variations in one gene can effect drug responsiveness

17
Q

effect of CYP2D6 mutation on tamoxifen therapy?

A

mutates can either be: ultra rapid or poor metabolizers.
CYP2D6 metabolises tamoxifen
can lead to sub therapeutic levels or overdose.

18
Q

what do histones organise?

A

genetic material

19
Q

what are histones made of

A

protein

20
Q

charge of histones?

A

positive as they have a high percentage of basic amino acids

21
Q

why do these histones associate with DNA

A

as the positive amino acids interact with the negatively charged DNA

22
Q

How can histones influence gene expression

A

the tighter the association, the more wound it is and therefore less transcription

23
Q

what is the most compact shape called of dna and hhistone association. the dna here is ______

A

heterochromatin

inactive

24
Q

what is euchromatin

A

nucleosome structure made of four histones ‘core histones’

contains a single copy of genetically active DNA

25
Q

what does the epigenome influence?

A

which genes are active and which are turned off

26
Q

TF the epigenome cannot change in your life

A

false

27
Q

TF lifestyle and environment can change the epigenome

A

yes

28
Q

where do epigenetic changes mostly occur?

A

on histone proteins

29
Q

epigenetic changes on histone proteins include?

A

methylation, acetylation, phosphorylation, ubiquitination

30
Q

_____ and ______ resides can be methylated

A

lysine

arginine

31
Q

what is acetylation?

A

addition of acetyl groups on lysine resides

32
Q

what is acetylation of lysine resides on histones catalysed by?

A

histone acetyltransferase enzymes

33
Q

what catalyses deacetylation?

A

histone deacetylases

34
Q

acetylation is associated with _______ of transcrption

deacetylation is associated with _______ of transcription

A

induction

repression

35
Q

TF

cancers are caused only by changes to the genome not the epigenome

A

false

a combination

36
Q

what were histone deacetylase 1 and 2 both correlated with?

A

increased proliferating capacity

37
Q

what can DNA hypermethylation cause? where is this often seen?

A

transcriptional inactivation of genes

observed in tumours

38
Q

a decrease in DNA methylation ______ genes

A

activates

39
Q

how can we use a therapy to result in the re-expression of transcriptional incompeted chromatin

A

inhibit certain active histone methyltransferases

can lead to repression of genes

40
Q

decitabine and azacitidine mechanisms of action?

A

blocks DNA methyltransferase causing hypomethylation of DNA

may reverse inactivation of suppressor genes

41
Q

decitabine and azacitidine side effects

A

bone marrow suppression

cytotoxicity

42
Q

in carcinogenesis how can TSGs be silenced. how can we target this

A

by DNA methylation

so can use a drug to inhibit DNA methyltransferases to re express the TSGs

43
Q

MOA of temozolomide

A

kills cancer cells by adding methyl groups to DNA

44
Q

decitabine is a _______ ______. what does it inhibit

A

nucleoside analoge

inhibits DNA methyltransferases by trapping them in a covalent complex on DNA thus resulting in enzyme degradatoin