Cystic Fibrosis

Question 1

What is cystic fibrosis?

Answer 1

Inherited genetic disorder that affects the lungs and the digestive system.

Question 2

What is the genetic cause of cystic fibrosis?

Answer 2

Autosomal recessive mutation in the cystic fibrosis transmembrane conductance regulator gene (CFTR) on chromosome 7 which codes for a cAMP-regulated Na/Cl channel.

Question 3

What is the main clinical feature of cystic fibrosis in neonates?

Answer 3

Meconium ileus

Question 4

What is this a presentation of?

Infant, recurrent pneumonia and wheeze (+/- clubbing), failure to thrive, slow growth. Fatty, oily, pale stools.

Answer 4

Cystic fibrosis

Question 5

What is this a presentation of?

Child, delayed puberty, liver disease, diabetes mellitus.

Answer 5

Cystic fibrosis

Question 6

How is cystic fibrosis screened for?

Answer 6

1. Newborn heel prick test for abnormally raised immunoreactive trypsinogen and 29 CFTR gene mutations.
2. If both parents known to carry mutation - amniocentesis on foetus

Question 7

How is cystic fibrosis diagnosed?

Answer 7

1. Stool - faecal elastase
2. CXR - hyperinflation, atelectasis, bronchiectasis
3. Diagnostic sweat test - high chloride concentration (>60mmol/L), if 30-59mmol/L then repeat test.

Question 8

How are the respiratory problems in cystic fibrosis treated?

Answer 8

1, Chest physiotherapy (3x/d) - percussion and postural drainage to aid phlegm removal.
2. Inhaled hypertonic saline, bronchodilators and mucolytics as adjuncts.

Question 9

How are the gastrointestinal problems in cystic fibrosis treated?

Answer 9

1. Need a high fat, high calorie diet with pancreatic enzyme supplements.
2. Fat soluble vitamin supplements: A, D, E, K
3. Enzymes - Pancrex V for infants, Creon for older children.
4. Omeprazole aids absorption

Question 10

What are these medications used for in cystic fibrosis?

1. Lumacaftor
2. Ivacaftor

Answer 10

1. Increases number of CFTR channels

2. Increases chance that CFTR channels will open

Question 11

What is the main respiratory complication of cystic fibrosis, what causes it, and how is it treated?

Answer 11

Respiratory infection:

1. Staphylococcus aureus, streptococcus pneumonia.
2. Treat after sputum culture with IV antibiotics
3. Can be chronically colonised with pseudomonas aeruginosa.

Question 12

What is the main gastrointestinal complication of cystic fibrosis and how is it treated?

Answer 12

GI obstruction:

1. Meconium ileus equivalent in children
2. Gastrograffin

Question 13

What is the main endocrine complication cystic fibrosis, how is it screened for, and how is it treated?

Answer 13

Diabetes mellitus:

1. Screen yearly with OGTT from 12 years old.
2. Treat with insulin

Question 14

What are the hepatic complications of cystic fibrosis?

Answer 14

NAFLD and gallstones

Question 15

In which gender does cystic fibrosis cause infertility?

Answer 15

Male

Question 16

What is this describing?

Failure to postural or vomiting in the first 2 days of life.

Answer 16

Meconium ileus

Question 17

What is this a presentation of?

Newborn, abdominal distension, bilious vomiting, distended Loops of bowel on abdominal X-ray.

Answer 17

Meconium ileus

Question 18

What is the treatment for meconium ileus?

Answer 18

NG tube drainage, wash-out enema, surgical excision of bowel.

Question 19

What is the prognosis of cystic fibrosis?

Answer 19

1. Death may be from pneumonia or cor pulmonale

2. Most survive to adulthood, >50 years possible if born after 2000.