L7 - human genetic variation Flashcards Preview

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Flashcards in L7 - human genetic variation Deck (15):
1

what are some types of variations

snp
cnv
small del
other chr rearrangements

2

how can variation be detected

genotype - detect nt var
haplotyping - detect region of recomb
likage disequilibium

3

what are some porjects that have tracked haplotypes

hapmap
1000 genomes project

4

what is the hapmap project looked at

haplotpyes of inds from 4 pops
detect snp to determine the haplotype

5

what are the findings from the hapmap project (snp)

between 2 ind are 3mil diff in snp
0.1% of genome varies between 2 ind (not accounting for cnv and inversions)
more var in yoruba and kenyan pop tahn eu and am

6

what are the findings from the hapmap project (cnv)

73-87 genes differ between 2 ind due to cnv
vary in ethinic grp
cnv in certain genes in humans more variable than apes (geen family expansion - unique to humans)
cnv pot role in schizophrenia/epilepsy as map to disease region found by gwas

7

what are cnv

segemental uplication of genes aar pf recombination defects
(unequal crossing over where there is low complexitiy)

8

what the differenc between hapmap and 1000 genomes

14 pops studied
greater resolution inc strucutral variants
captued 95% of human genetic var

9

what did the 1000 genomes project discover

individuals carry more than 25000 non synonymous variations in regions conserved across sp
20-40% of variation is potentially damaging
25-50% of rare variations are deleterious

10

what did the phas111 of the 100 genomes project show

looked at whole genome and exome of inds from 26 pops
>99% variants are snp and short indels
strucutral variants are rarer but encompass arger bp , 18.4mbp per genome =much of which occur in pseudogene area

11

what were the findings on cnv study by sudamant et ak 2015

size median 7369bp
82% <25kbp
incr size of cnv incr risk pathological
del more common than dup (suggest del more patho)

12

what were the main findings from the african genome project

ethiopian pop had highest unshared variation
evidence of huntergatherer and eu admix in afri pop
some genes showed had selection on - gene in malaria and another on osmoregulation

13

what was teh finding of eu admix in african populations

in yoruba pop 7.5kya
in ethipoian 2.4-3.2kya
in e.africa 150-1500ya
support finds of non zero neanderthal in yoruba - prbs aar of eu admix

14

what genes were found to show selection in the african genome project

CR1 gene inv in malaria suseptibility - found sel for variant in malaria epidemic zone
AQP2 inv in osmoreg dergeg of - hypertension
pot adv in climate to not have high burden hypertension

15

what revealed when comparing cnvs of fibroblasts and neurones

more variable in neurones
neurone cnv specific to ind cell
- somatic cell mosaic in variation