cystic fibrosis Flashcards
inheritance
autosomal recessive
genetic mutation of
cystic fibrosis transmembrane conductance regulatory gene
chr 7
what does CF gene code for
type of chloride channel
key consequences of CF mutation
- thick pancreatic and biliary secretions
- low volume thick airway secretions
- congenital bilateral absence of vas deferens
thick pancreatic and biliary secretions
cause blockage of ducts
results in lack of digestive enzymes e.g. pancreatic lipase, in digestive tract
Low volume thick airway secretions
reduce airway clearance
results in bacterial colonisation and susceptibility to infection
Congenital bilateral absence of the vas deferens
male infertility
both parents are healthy, one sibling has cystic fibrosis and a second child does not have the disease, what is the likelihood of the second child being a carrier?
2 in 3
presentation
picked up at newborn bloodspot test screening meconium ileus recurrent LTRIs FTT pancreatitis
symptoms
chronic cough thick sputum recurrent RTIs steatorrhoea abdo pain + bloat FTT
signs
low weight and height nasal polyps clubbing crackles & wheeze abdominal distension
key methods for establishing diagnosis
newborn blood spot testing
sweat test ***
genetic testing on CFTR gene
sweat test
gold standard
diagnostic = chloride concentration >60mmol/L
common microbial colonisers
staph aeureus h influenza pseudomonas e coli klebsiella
colonisation with pseudomonas aeruginosa
can be very difficult to get rid off - can. become resistant to multiple antib
increase morbidity and motrality
avoid contact with other CF to minimise risk transmission
