cystic fibrosis

Question 1

inheritance of cystic fibrosis

Answer 1

autosomal recessive disorder

Question 2

what is cystic fibrosis

Answer 2

increased viscosity of secretion (lungs and pancreas)
due to defect in cystic fibrosis transmembrane conductance regulator gene (CFTR) which codes a cAMP- regulated chloride channel

Question 3

organisms which may colonise CF patients

Answer 3

staph aureus
pseudomonas aeruginosa
burkholderia cepacia
aspergillus

Question 4

presenting features of CF

Answer 4

neonatal period: meconium ileus, prolonged jaundice
recurrent chest infections
malabsorption: steatorrhoea, failure to thrive
liver disease

Question 5

other features of cystic fibrosis

Answer 5

short stature
diabetes
delayed puberty
rectal prolapse
nasal polyps
male infertility

Question 6

diagnosis of CF

Answer 6

sweat test: > 60 (high sweat chloride)

Question 7

causes of a false positive sweat test

Answer 7

malnutrition
adrenal insufficiency
glycogen storage diseases
nephrogenic diabetes insipidus
hypothyroidism, hypoparathyroidism
G6PD
ectodermal dysplasia

Question 8

management of CF

Answer 8

regular chest physio and postural drainage
high calorie and high fat diet
vitamin
pancreatic enzyme supplements with meals
lung transplantation (not if chronic infection with burkholderia cepacia)
lumacaftor/ivacaftor- for CF patients who are homonzygous for delta F508