Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MCB1 Block 4 > Dominant Negative Mutations > Flashcards

Dominant Negative Mutations Flashcards

1
Q

What is a dominant negative mutation?

A

mutant gene product interferes w/ function of normal gene product

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

what kinds of proteins are usually affected by dominant negative mutations

A

structural proteins like collagen

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

What does OI stand for

A

osteogenesis imperfecta

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

What is mode of inheritance for OI

A

AD

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

A more severe mutations leads to what kind of phenotype vs. less severe in OI

A

more severe mutation is less severe phenotype

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

OI has significant clinical ______

A

heterogenity

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

What protein is affected in OI

A

Type I Collagen

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

What two genes are involved in OI

A

proalpha 1 (COL1A1) and proalpha2 (COL1A2)

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

presentation: weak bones, increased frequency of fractures, possible bone deformities, short stature, blue sclera, significant clinical heterogeneity is what disease

A

OI

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

What type of treatments are there for OI

A

supportive

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

What is structure of collagen

A

triple helix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What aa are in alpha chain of collagen

A

Gly-X-Y
X is usually proline
Y is usually hydroxyproline or hydroxylysine

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

What kind of mutations cause type I OI?

A

null mutations

haploinsufficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is mildest form of OI

A

type I

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

What kind of mutations cause Type III-IV

A

missense

dominant negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is most severe form of OI

A

type II

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is phenotype of type II OI

A

fetus dies :(

AKA perinatal lethal

18
Q

Why is OI unique in regards to mutations and phenotype

A

null mutation causes milder phenotype: type I

missense mutation cuases more severe phenotype like Type II

19
Q

Severe forms of OI are almost always due to _____ missense mutations

A

sporadic

20
Q

What is intermediate form of OI

A

Type III & IV

21
Q

Where are missense mutations in Type II OI?

A

glycine resides of collagen

22
Q

COL1A1 produces what

A

alpha 1 chain of collagen

23
Q

COl1A2 produces what

A

alpha 2 chain of collagen

24
Q

What happens if there is a missense mutation on one locus of COL1A1

A

if glycine is mutated to some other aa it will cause a bend or kink in structure of colagen

25
Q

How is OI dominant negative

A

one missense mutation causes a negative affect on the other two collagen strands and the collagen as a whole, so it is dominant and creates a negative affect on the other two alpha chains, producing a bad structure

26
Q

If there is a missense mutation and produces OI, how much collagen produced is normal?

A

1/4 is normal 3/4 is abnormal

27
Q

How does collagen winding proceed?

A

C to N terminus

28
Q

closer mutation is to C terminus, what happens

A

winding stops

29
Q

when collagen hits kink what happens to its winding

A

it stops

30
Q

In OI how much collagen is excreted from cell

A

only 1/4

3/4 is trapped in cell

31
Q

The closer the mutation is to C terminus, the more ___ the OI disease

A

severe

32
Q

What types of mutations cause type I OI

A

null mutation

33
Q

What happens if there is an entire gene deletion of COL1A1?

A

1/2 as much alpha 1 is produced, but all that is produced is normal

34
Q

Is there dominant negative affect in type I OI?

A

No

35
Q

how much triple helical collagen is produced in type I OI?

A

1/2 as much

36
Q

What is the structure of the collagen produced in Type I OI?

A

normal

37
Q

If OI is AR what will mtuation be

A

abnormal collagen modification but no COL1A1 o COL1A2 mutation

38
Q

clinical severity in AR OI is what

A

highly varibale

39
Q

AR OI is deficient for enzymes involved in what

A

post-translational modification

40
Q

What mutation causes stickler syndrome

A

Null mutation of type II collagen

41
Q

Dominant negative missense mutations result in more ____ chondroplasias

A

severe

42
Q

Severe myopia, brother short born with cleft palate, father short, bilateral hip replacements, reintal detachment is what disease

A

stickler syndrome

MCB1 Block 4 (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions