Non-classical genetic mechs. in health and disease

Question 1

why are twin fingerprints diff.

Answer 1

genes - similar pattern type and ridging

env. in utero - diff. where ridges meet end or bifurcate

Question 2

how do ID twins become diff

Answer 2

somatic and lifestyle factors

Question 3

how does methylation affect genes

Answer 3

no meth - expressed

meth - not expressed

Question 4

how is methylation important (3)

Answer 4

1. important in intrinsic reg. of gene dosage
2. involved in lifelong genomic adaptations and response to env. stressors
3. can ID monozygote twins

Question 5

how does X and Y differ

Answer 5

X gene rich, Y poor

Question 6

what is X inactivation

Answer 6

inactivate one X to control gene dosage

Question 7

what is skewed x inactivation

Answer 7

end up inactivating the good gene

Question 8

what is imprinting

Answer 8

certain genes in autosome chromosomes unergo silencing bia meth or histone

Question 9

what is effect of imprinting

Answer 9

genes from ONE parent are expressed, not both

Question 10

how do imprinted genes present

Answer 10

dose sensitive

Question 11

what is mosaicism

Answer 11

get at least two cell lines of a differing genotype from the same zygote

Question 12

what causes masiaicms

Answer 12

mitotic mistake

Question 13

what is temporal effect of misaicsm

Answer 13

earlier will be more widespread

Question 14

what happens in germline mosaisism

Answer 14

bb will be all the same

Question 15

what happens if mutation is picked up in the skin, but the germ line is fine

Answer 15

bb won’t be affected

Question 16

what is neurofibromatosis1 (NF1)

Answer 16

• cafe-au lait spots
• fezking-
• nodules
• learning dis.

Question 17

what is mitochondial DNA

Answer 17

special circular DNA that codes 37 genes

Question 18

how does mito DNA mutate

Answer 18

sensitive to env. effects

• rad
• pesticides
• viruses

Question 19

what happens with more mutations

Answer 19

at some point get enough mutation that can’t produce E effectively

Question 20

what may be outcomes in children with mother of mito mosaicism

Answer 20

could be fine, but also spectrum to severe probelms

Question 21

what is fragile X effects

Answer 21

lots of mental health problems

Question 22

what causes fragile X (FMR1)

Answer 22

of CGG repeats

• the more repeats, the less FMRP protein
• less protien, more problems

Question 23

what is FMR1 full mutation

Answer 23

fragile X - variable based on number of CGG repeats

Question 24

what is FMR1 premutation (3)

Answer 24

1. premature ovarian failure
2. tremor ataxia syndrome
3. incre. risk of psych

Question 25

what are triplet repeat expansion disoreder

Answer 25

expansion of a segment that has these releaps

Question 26

what is anticipation

Answer 26

progressively earlier onset of problems in generations with disorder bc repeats expand over generations

Question 27

what are gene-dose effects for skewed x inactivation

Answer 27

X linked disorders in females

Question 28

what are gene-dose effects for impriting

Answer 28

essential for normal growth dev. and behaviors

Question 29

what are gene-dose effects for mosaicism

Answer 29

somatic mutaiton load

- gonadal mosaiscsm

Question 30

what are gene-dose effects for mitochondiral heteroplasmy

Answer 30

mutation load

Question 31

what are gene-dose effects for trpilet repeat disoredse

Answer 31

more repeats, more problems