Cystic Fibrosis Patho Flashcards
Which chromosome is the CFTR gene located on?
Chromosome 7
Class II mutation of CFTR causes a defect in which part of the cell?
Golgi Apparatus
Class I mutation of CFTR causes a defect in which part of the cell?
Nucleus
What happens to the CFTR protein due to a a Class I mutation?
error in protein production, no CFTR protein created
What happens to the CFTR protein due to a a Class II mutation?
error in protein processing; protein is created but misfolded, keeping it from reaching cell surface
What happens to the CFTR protein due to a a Class III mutation?
error in gating; protein created and reaches cell surface but does not function properly
What is the order of prevalence of CFTR mutations?
Class II»_space; Class I > Class III ~ Class IV > Class V/VI
Which classes of CFTR mutations are more severe?
Classes I-III
Which is the most common gene sequence mutation for Class I?
G542X
What is the most common gene sequence mutation for Class II?
F508del
What is the most common gene sequence mutation for Class III?
G551D
What happens to the CFTR protein due to a Class IV mutation?
error in conduction; the opening in the protein ion channel is faulty
What is the most common gene sequence mutation for Class IV?
R117H
What happens to the CFTR protein due to a Class V mutation?
decrease in CFTR protein production; CFTR protein is created but in insufficient quantities
What happens due to sweat and sweat ducts due to CFTR mutation?
-Cl and Na are not reabsorbed
-abnormally high NaCl in sweat (diagnostic marker)
What happens in the lungs due to CFTR mutation?
-poor or no Cl transfer across airway due to CFTR protein defect, Cl build-up in cells
-influx of Na out of airway into cells to balance negative charge (
-water follows Na, what is left in airway is thick dehydrated mucus
-airway obstruction which leads to inflammation and bacterial infection
Besides the lungs, what other organs are affected by CF?
-sinuses
-skin
-liver
-pancreas
-intestines
Which bacterial pathogens are most common in younger patients (children and young adolescents)?
- S. aureus
- P. aeruginosa
Which bacterial pathogens are most common in older patients?
- P. aeruginosa
- S. aureus
What are the symptoms of CF?
-cough
-sputum production
-SOB
What are some signs of CF?
-reduced FEV1 and FVC
-crackles/rales
-rhonchi
-wheezing
-recurrent pneumonia
-hyperinflation/atelectasis
-late stage: pulmonary HTN
What symptoms of pancreatic dysfunction do CF patients have?
-fatty stools
-indigestion
-abnormal pancreas function
Exocrine dysfunction results in decreased production of what enzymes and electrolytes in CF patients?
-deficient protease, amylase, and lipase
-deficient bicarbonate
What does long-term exocrine dysfunction in CF lead to?
acinar cell destruction -> fibrosis -> progressive adipose replacement of pancreatic tissue
Exocrine dysfunction results in poor absorption of what in CF patients?
-Vitamins A, D, E, K (fat-soluble)
-Zinc
What is the pathophysiology of CFRD?
-islet destruction due to exocrine tissue destruction
-potential beta cell defect
What does CFRD cause?
-decreased insulin and glucagon secretion
-insulin resistance: dynamic, variable, and progressive
True or false: CF patients with diabetes are ketosis prone
FALSE.
True or false: CFRD involves autoimmune destruction of beta cells
False
Is CFRD associated with macrovascular or microvascular complications?
microvascular
