CF Flashcards
Syndrome of
chronic sinopulmonary infections, malabsorption and nutritional abnormalities
CF gene encodes for the _______ protein
cystic fibrosis transmembrane conductance regulator (CFTR)
CFTR functions as _______ and controls
- an ion channel
- the movement of salt and water into and out of cells
Mutations in the CFTR gene impair
this movement, critically altering host defense in the lung
_______ inheritance. CF gene is a large gene on chromosome _. _______ is the most common mutation
- Autosomal recessive
- 7
- deltaF508
CFTR protein is a member of the _______ superfamily and expressed in the _______.
- ATP-binding cassette
- epithelial cells lining the exocrine glands
CFR protein has ________ membrane spanning domains, __ nucleotide-binding domains and a unique, highly charged _______ domain.
- 2 six-span
- 2
- regulatory
Diagnosing
- newborn screen
- sweat test (>60 mmol/L)
CF tx
potentiator: Ivacaftor
Mutations in CF tend to cause either:
(1) no protein synthesis
(2) misfolding of protein leading to degradation before reaching apical cell surface
(3) altered conductance such that the protein can’t be conveyed to the apical surface, or
(4) partial loss-of-function such that the CFTR proteins don’t work as well as normal.
_______ and _______ are the most common pathogens found in CF lungs (since the mucus is an ideal breeding ground for bacteria).
- Pseudomonas
- Staphylococcus aureus
In lung: CFTR normally excretes _______ to move _______ into the mucus layer overlaying the lung epithelium (like in the intestine). With defective CFTR, _______
- Cl-
- water
- this water secretion doesn’t happen
normal CFTR also downregulates _______. Without CFTR, have elevated levels of _______, which further removes water from the lumen (and the mucus) into the epithelial cells, exacerbating the _______.
- epithelial sodium channels
- import of Na+ into epithelial cell
- thickness of the mucus
in sweat glands, the CFTR defect causes a problem in _______, as opposed to in the lung and intestine, where the defect causes a problem in _______
- getting chloride into the epithelial cells
- getting them out
Treat (lungs) with
airway clearance therapy, antibiotics to keep lungs clear, inhaled mucolytics (break up the mucus), brochodilators, enzyme replacement, vitamin A/D/E/K replacement, azithromycin used chronically