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Flashcards in epigenetics Deck (24)
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1

define epigenetics

Chemical modifications to the DNA and DNA-associated structures that do not change the DNA sequence, but can regulate gene expression and can be inherited across mitotic cell division

2

list seven key epigenetic modifications

DNA methylation, histone marks, promoter binding, enhancer binding, chromatin structure, position relative to nuclear lamina, chromatin interactions

3

name 3 atlases which can be used to look up epigenetic data to assist clinicians

The ENCODE Project
NIH Epigenome ROADMAP
The BLUEPRINT Project

4

describe process of dna methylation what, enzyme does it use and what part of dna does it act on commonly?

5MC and methyltransferase

5

why is 5 methyl cytosine commonly methylated

most stable human marker

6

what context does 5mc occur in mammals specifically humans

cpg island

7

what are the Roles of DNA methylation in normal development and over the life course

Gene expression regulation ‣ Reprogramming: cell lineage & tissue differentiation ‣ Genomic stability ‣ Genomic Imprinting ‣ X-chromosome inactivation ‣ Human Disease

8

if cpg cluster/island is in promoter region is gene likely to be on or off

likely to be switched off methylation in this area often results in this, whereas in gene body can cause switching on of gene

9

if gene is paternally imprinted which allele is expresses maternal or paternal

paternal therefore turned off so maternal

10

What are the symptoms of prader willi syndrome

constant hunger, obese, short stature, small hands and feet, mild mental retardation

11

What causes Prader willi syndrome

Maternal UPD because paternal gene is imprinted need father allele to function or 15q11 deletion

12

symptoms of Angelmans syndrome

happy disposition, wide mouth, gaps between teeth, mentally retarded severe, jerky movements

13

what uniparental disomy can cause angelmans syndrome

paternal upd

14

what are symptoms of beckwith wiedemman syndrome

Overgrowth Cancer pre-disposition Macrosomia (large birthweight) Macroglossia (large tongue), prominent eyes Accelerated bone age Growth asymmetry Enlargement of kidneys, liver, pancreas, and spleen Neonatal hypoglycemia (30%) Cardiovascular defects

15

what causes bws

Dysregulation of imprinting control regions on chromosome 11

16

what has been noted in IVF births with regards to BWS

increased incidence

17

describe some symptoms of silver Russel syndrome

triangular face, growth asymmetry especially of limbs, a lot of minor malformations, small in curved fifth fingers

18

what causes silver Russel syndrome

First human disorder with imprinting disruptions affecting two or more different chromosomes (chromosome 7 and 11).

19

what is X chromosome inactivation

it is the random silencing of one of the x chromosomes in each of the cells in order for female development to proceed. dosage compensation

20

state some diseases that random x inactivation has been associated with

haemophilia, Fragile-X syndrome, and Duchenne Muscular Dystrophy

21

what has gwas found in study of cancers

cancerous cells have gross change in epigenetic structure

22

why is it important to control child exposure to risk factors

Exposures in development (prenatal, foetal, and postnatal) lead to greater susceptibility to human disease in later life

23

what does maternal smoking during pregnancy do

can induce epigenetic changes causes epigenetic disease and congenital defects as a result

24

what does poor nutrition do to foetus

Dutch Hunger Winter Study: food restriction in utero has adverse effects on metabolism and cardiovascular health, and age-associated decline of cognitive functions2. Epigenetic analyses show persistent epigenetic changes associated with prenatal exposure to famine