Lecture 8: Cystic Fibrosis Flashcards
What is the mode of inheritance; encoded protein and chromosome involved in cystic fibrosis?
- Autosomal recessive
- CFTR encodes protein that functions as cAMP regulated Cl- channel across epithelial cells on mucosal surfaces
- Chromosome 7
CF is a disease of which glands?
Exocrine gland function (i.e., tubules, ducts, lungs, pancreas, liver, intestines, and gonads)
Which ethnic group has the highest carrier frequency for CF?
Ashkenazi Jews
If Mom and Dad are a carrier of CF gene what % of kids will be carriers, have CF, and not be affected?
- 50% will be carriers
- 25% will have CF
- 25% will not have CF or be a carrier
Why does CF not present the same way in every patient?
CFTR mutations have poor penetrance
The most common clinical presentations of CF include what 2 things?
- Chronic and progressive lung disease
- Exocrine pancreatic insufficiency
CF sx’s are highly varies among individual pts, even btw siblings who carry identical CFTR alleles, and the variation is thought to be influenced by which 2 factors?
- Non-genetic factors –> enviornmental, nutritional, age of onset
- Modifier genes
What are the most common organisms to colonize the lungs during early childhood; but ultimately which bacteria will be isolated from the respiratory secretions of pt with CF?
- S. aureus and nontypeable H. influenzae = most common
- Eventually Pseudomonas aeruginosa is ultimately isolated = not good
What is the most common cause of death in pt’s with CF?
Respiratory failure and cor pulmonale
Which GI finding is commonly seen in neonates with CF while in the nursery?
Meconium Ileus
Which vitamins must be supplemented in CF pt’s?
Fat-soluble (ADEK)
Which endocrine abnormality is commonly seen in pt’s with CF?
Diabetes mellitus
Plugging of the biliary ductules in CF can lead to what liver pathology?
Obstructive cirrhosis
Most men with CF will have reduced fertility due to what?
Azospermic secondary to agenesis of the vas deferens
What’s a common ENT finding in child with CF?
Nasal polyps
What are the 2 major criteria for diagnosis of CF?
- A positive newborn screening test
PLUS
- An elevated sweat [Cl-] on 2 or more occasions
The newborn screening for CF is a test for what?
Immunoreactive trypsinogen (IRT) –> typically elevated in CF
