Non-classical genetic mechs. in health and disease Flashcards
why are twin fingerprints diff.
genes - similar pattern type and ridging
env. in utero - diff. where ridges meet end or bifurcate
how do ID twins become diff
somatic and lifestyle factors
how does methylation affect genes
no meth - expressed
meth - not expressed
how is methylation important (3)
- important in intrinsic reg. of gene dosage
- involved in lifelong genomic adaptations and response to env. stressors
- can ID monozygote twins
how does X and Y differ
X gene rich, Y poor
what is X inactivation
inactivate one X to control gene dosage
what is skewed x inactivation
end up inactivating the good gene
what is imprinting
certain genes in autosome chromosomes unergo silencing bia meth or histone
what is effect of imprinting
genes from ONE parent are expressed, not both
how do imprinted genes present
dose sensitive
what is mosaicism
get at least two cell lines of a differing genotype from the same zygote
what causes masiaicms
mitotic mistake
what is temporal effect of misaicsm
earlier will be more widespread
what happens in germline mosaisism
bb will be all the same
what happens if mutation is picked up in the skin, but the germ line is fine
bb won’t be affected
what is neurofibromatosis1 (NF1)
- cafe-au lait spots
- fezking-
- nodules
- learning dis.
what is mitochondial DNA
special circular DNA that codes 37 genes
how does mito DNA mutate
sensitive to env. effects
- rad
- pesticides
- viruses
what happens with more mutations
at some point get enough mutation that can’t produce E effectively
what may be outcomes in children with mother of mito mosaicism
could be fine, but also spectrum to severe probelms
what is fragile X effects
lots of mental health problems
what causes fragile X (FMR1)
of CGG repeats
- the more repeats, the less FMRP protein
- less protien, more problems
what is FMR1 full mutation
fragile X - variable based on number of CGG repeats
what is FMR1 premutation (3)
- premature ovarian failure
- tremor ataxia syndrome
- incre. risk of psych
what are triplet repeat expansion disoreder
expansion of a segment that has these releaps
what is anticipation
progressively earlier onset of problems in generations with disorder bc repeats expand over generations
what are gene-dose effects for skewed x inactivation
X linked disorders in females
what are gene-dose effects for impriting
essential for normal growth dev. and behaviors
what are gene-dose effects for mosaicism
somatic mutaiton load
- gonadal mosaiscsm
what are gene-dose effects for mitochondiral heteroplasmy
mutation load
what are gene-dose effects for trpilet repeat disoredse
more repeats, more problems
