Genetic medicine in systems Flashcards

1
Q

how do pathogenic variants cause disease? (4 different ways)

A
  1. null variants
  2. gain of function variants
  3. dominant negative variants
  4. loss of heterozygosity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are null variants?

A

= when gene stops making peptide

  • premature stop codon
  • frameshift
  • splice mutation
  • gene deletion

e.g. marfan syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is haploinsufficiency?

A

haploinsufficiency = less functioning protein so cell can’t make stuff it needs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is gain of function variants type of pathogenic variant causing disease?

A

= variant leads to peptide with gain of or new function

  • missense variants
  • activates the genes

e.g. hypochondroplasia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is dominant negative variants?

A

= variant leads to peptide that interferes with another peptide

  • missense variant
  • makes abnormal collagen

e.g. osteogenesis imperfecta type 2

abnormal collagen messes up normal peptide

2 peptides need to work together - 1 peptide messes with the other. variant leads to peptide that interferes with another peptide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is loss of heterozygosity?

A

= first null copy is inherited somatic loss of second copy

  • fist null copy

inherits 1 germline variant - gets 2nd somatic variant means can no longer

second allele lost in cell

(i think it’s like the cancer - need 2 hits)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

when can genetic therapy be used? at what point?

A

at every point in central dogma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how does treatment work for genetic diseases?

A

it has to be very highly specific - not just to disease but specific to the genetic variant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

how do you treat null pathogenic variants?

A

You need to replace the gene of the mRNA (as peptide has stopped being made due to premature stop)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how do you treat gain of function or dominant negative mechanisms?

A

You need to reduce mutant gene expression

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are the risks of integrating gene therapy?

A
  • Disruption of important genes (“Off Target effects”)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the negative of mRNA knockdown or mRNA gene replacement?

A

Need for repeated treatment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are the risks for viral vectors to deliver gene therapy?

A
  • Immune reaction to the vector
  • Immune reaction to the transfected cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is the big negative for all the developments for genetic disease treatment?

A

unaffordable and unsustainable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are precision therapies targeted at?

A

specific causative variant (not everyone with a disease)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly