Cystic Fibrosis Flashcards
What is the name of the gene disorder that causes cystic fibrosis?
Cystic fibrosis transmembrane conductance regulator
What are the systems affected by CF?
Upper and lower respiratory tract
Pancreas
Gastrointestinal tract
Female/Male reproductive tract
What criteria must be met in order to diagnose cystic fibrosis?
Clinical symptoms consistent with CF in at least one organ system
Clinical evidence of CFTR dysfunction
Describe the ethnic distribution of CF
Most prevalent in caucasians by a wide margin
Least prevalent in asians
No fucking clue why
Being pasty as fuck may be a contributing factor
When are most cases of CF diagnosed?
Most are caught at birth via standard testing
Mutations on which chromosome are responsible for CF?
7
How many different mutations can cause CF?
According to steves slides, 2400. According to steves other slides, 24000. According to google, over 2000
CF is an autosomal recessive gene disorder. What is the significance of this
In order to be affected by the disease, both parents have to have the disease causing mutation, even if neither parent has the disease. Both parents can be carriers, but not be affected by the mutation since it is recessive
T/F: CF is a classical autosomal dominant gene disorder
False. CF is a classical autosomal recessive gene disorder
If one parent is a carrier, and one parent has CF, what are the chances that their children will be affected by the mutation?
50% chance of being affected
50% chance of being an unaffected carrier
If both parents are carriers, what are the chances that their offspring will be affected by the mutation?
25% unaffected
50% unaffected carrier
25% chance affected
If one parent is a non carrier, and one parent has CF, what are the chances their children will be affected by the mutation?
100% chance unaffected carrier
If one parent is a non-carrier, and one parent is an unaffected carrier, what are the chances that their children will be affected by the mutation
50% unaffected
50% unaffected carrier
What physiologic process does the CFTR gene regulate?
It regulates the conductance of chloride ions across the membrane
What effect does a mutation of the CFTR gene have?
It interferes with the production of the CFTR gene in a way that either completely halts the creation of the protein, completely or partially inhibits its ability to conduct ion transport, causes production of the protein to be significantly less than normal, or causes the protein to deteriorate at an advanced rate
What are the primary organs/areas that experience issues as a result of CFTR dysfunction?
Lining of of bronchial airways
Intestines
Pancreas
Liver ducts
Sweat glands
Describe the primary effect a mutation of the CFTR gene has on the respiratory tract
The mutation interferes with chloride transport in the bronchial airways. This in turn interferes with how fluid moves across the membrane from the mucus into the epithelium. As a result, there is a very low concentration of ions in the mucus resulting in fluid moving out of the mucus and into the epithelium creating a very tenacious mucus that is very difficult to clear
Describe how CF can affect infants before they are born
The mutation results in the infants meconium becoming dehydrated and sticky. This material is very difficult to pass and can create an ileus (blockage) in the intestines
What percentage of infants with CF are affected by meconium ileus?
About 20%
At birth, an infant with CF may have lungs that appear normal, however structural changes can develop quickly. What are examples of these structural changes?
Bronchial gland hypertrophy
Metaplasia of goblet cells
Infants with CF might exhibit what problems aside from meconium ileus?
Poor weight gain
Failure to thrive
Multiple respiratory infections per year
Consistent cough with sputum production
Pancreatic insufficiency
T/F: CF has obstructive and restrictive characteristics
True
CF results in mucus that is incredibly hard for individuals to clear. Besides airway restrictions, describe what other effects this incredibly thick mucous can have on patients
The mucus traps bacteria, however because patients are not able to clear this bacteria via normal means, the trapped bacteria becomes a food source for retained bacteria in the airway such as staph, haemophilus and pseudomonas
What are restrictive characteristics of CF?
Total obstruction of airways
Atelectasis
Bronchiectasis