Cystic Fibrosis

Question 1

Problem in class I cystic fibrosis? 
Class II?
Class III?
Class IV?
Class V?
Class VI?

Answer 1

I- absence of synthesis
II- defective protein maturation and premature degradation.
III- disordered regulation, such as reduced ATP binding and hydrolysis.
IV- defective chloride conductance or channel gating.
V- a reduced number of CFTR transcripts due to promoter or splicing abnormality.
VI- accelerated turnover from the cell surface.

Question 2

CTFR promoter regions have a lot or few mutations.

Answer 2

few. they are rare.

Question 3

Problem in Class I cystic fibrosis?

Answer 3

absence of synthesis

Question 4

What does gentamycin do?

Answer 4

Supresses recognition of premature stop codon, if this is the problem.

Question 5

G551D mutation involved in what class?

Answer 5

Class III

Question 6

A455E mutation is in what class? Function?

Answer 6

Class IV. Partial function.

Question 7

Calnexin and Hsp70 do what?

Answer 7

They are chaperone proteins that help in the folding of CFTR

Question 8

What mutation is most common at about 90%? Results in what? Treatment options? What do these do?

Answer 8

F508. Results in increased level of misfolded protein, and targeted for ERAD. Correctors and Potentiators for treatment. Correctors restore defective cell tracking, so things can get to the surface in the first place. Potentiators improve dysfunctional channel properties.

Question 9

How is postnatal screening done? how about for carriers?

Answer 9

Post natal is sweat test. Carrier uses multiplex PCR assay