Cystic Fibrosis in Children and Adults

Question 1

Is cystic fibrosis dominant or recessive?

Answer 1

Recessive

Question 2

How do you get a recessive disease like CF?

Answer 2

Inheriting two copies of the mutated gene, one from each parent.

Question 3

In which group is CF the most common autosomal recessive disorder?

Answer 3

Caucasians (white people)

Question 4

How many people are carriers of CF?

Answer 4

1in 25

Question 5

What is the most common mutation seen in CF patients?

Answer 5

Delta 508

Question 6

What is the main cause of morbidity and mortality in those with CF?

Answer 6

Pulmonary disease

Question 7

What % of deaths in those w CF is due to respiratory failure?

Answer 7

90%

Question 8

If both parents are affected, what are the chances the child will be affected?

Answer 8

1 in 4
25%

Question 9

If both parents are affected, what is the chance the child will be a carrier?

Answer 9

2 in 4
50%

Question 10

If both parents are affected, what is the chance that the child will be unaffected?

Answer 10

1 in 4
25%

Question 11

What is the chromone pair which CF affects?

Answer 11

Chromosome pair 7

Question 12

Which protein does the mutation occur?

Answer 12

Transmembrane conductance regulator protein

Question 13

What happens to the cell due to abnormal function of the protein channel?

Answer 13

Chloride is trapped in the cell. Sodium and water then follow chloride and flow into the cell

Question 14

What can the abnormal chlorine and sodium transport cause to happen?

Answer 14

Dehydrates mucous layer meaning reduced airway liquid
Thick sticky mucous forms

Question 15

How does the abnormal chlorine and sodium transport affect bacteria levels?

Answer 15

There will be impaired bacteria killing via neutrophils

Question 16

How many mutation classes are there for CF?

Answer 16

6

Question 17

Which mutation classes cause the more severe cases of CF?

Answer 17

Classes 1-3 due to no functioning protein

Question 18

Which mutation classes cause the milder CF?

Answer 18

Classes 4-6 due to some functioning protein

Question 19

If there is identification of a parent/sibling with CF, which antenatal tests can be done to test if the developing child has CF?

Answer 19

Pre-implantation genetic diagnosis
Chorionic villous sampling
Amniocentesis

Question 20

Which test can be used to test the baby for CF after birth?

Answer 20

Newborn bloodspot day 5 (Guthrie test)

Question 21

What can you test anytime postnatally to test for CF?

Answer 21

Sweat

Question 22

Describe why sweat is tested for CF.

Answer 22

Measure the chlorine conc. in sweat and will be elevated in those with CF

Question 23

Name the three outcomes of the combination of prenatal, antenatal and postnatal testing can give.

Answer 23

Have CF
Don’t have CF
Screen positive inconclusive diagnosis

Question 24

Which systems of the body can CF affect?

Answer 24

Any system of the body

Question 25

Name some of the main conditions which may indicated CF.

Answer 25

Pancreatic insufficiency Diabetes Infection and bronchiectasis

Question 26

What organ does the CFTR also affect?

Answer 26

The pancreas

Question 27

What effect does the CFTR mutation have on the pancreas?

Answer 27

Lack of enzymes to digest food hence leading to: Malabsorption Abnormal stools - pale, offensive, float Failure to thrive

Question 28

Classes 1-3 have what effect on the pancreas?

Answer 28

Pancreas is inefficient

Question 29

Classes 4-6 have what effect on the pancreas?

Answer 29

Pancreas has some function

Question 30

What can recurrent bronchopulmonary (chest) infection cause?

Answer 30

Pneumonia Bronchiectasis Scarring Abscesses

Question 31

List the reasons pulmonary infection may occur due to the CFTR abnormality.

Answer 31

-Abnormal electrolyte transport across cell membrane -Dehydration of airway surface layer (water later which allows mucous to slide easily up airway to be coughed up) -Decrease in mucociliary clearance -Mucous sticks to mucosal surface -Increased access to bacteria -Decreased bacteria killing

Question 32

What can mucous sticking to the mucosal surface do?

Answer 32

Causes shearing and inflammation

Question 33

Discuss the cycle of events which lead to repeated respiratory infections.

Answer 33

Firstly, I am sorry but if you read through, it makes sense! Got a lot of words :/ 1. Decreased mucus clearance, increase in bacteria adherence and a decrease in the endocytosis of bacteria 2. This leads to bacteria colonisation 3. This leads to inflammation, mucus plugging, airway ulceration and damage. 4. This leads to bronchiectasis and so the cycle continues xoxoxoxo

Question 34

What is the result of recurrent chest infections?

Answer 34

Progressive respiratory decline

Question 35

Which investigations can be used to diagnose CF?

Answer 35

CXR usually not enough alone so CT too

Question 36

What is meant by tramlines?

Answer 36

Thickened dilated airways that cannot clear mucus, often seen on CT in those w CF.

Question 37

What would you see on a CT in those with CF?

Answer 37

Tramlines Signet rings Mucous plugging Consolidation (infection)

Question 38

What is the treatment for pancreatic insufficiency in CF?

Answer 38

Boosting nutrition

Question 39

In terms of nutrition, what will be done in those with pancreatic insufficiency?

Answer 39

1. Replace enzymes 2. High energy plus high calorie supplement drinks 3. Fat-soluble vitamin and mineral supplements

Question 40

What is the treatment for mucus obstruction and inflammation?

Answer 40

-Airway clearance via physiotherapy -Mucolytics -Bronchodilators

Question 41

What is the treatment for chronic infection?

Answer 41

-Antibiotics, either oral, IV or nebulised

Question 42

Which antibiotic can be given to treat inflammation?

Answer 42

Azithromycin

Question 43

What management is provided for those with fibrosis/scarring/bronchiectasis?

Answer 43

Supportive treatment and management of symptoms

Question 44

The treatment in which condition differs in those with CF and those without CF?

Answer 44

Diabetes

Question 45

List some of the diabetic issues present in those with CF.

Answer 45

Compliance with diet a problem- need high calorie diet (unlike non CF diabetics) Insulin of benefit, not so much oral drugs Complication risk same as non CF pts but lung disease gets there first

Question 46

What can happen to the bones in patients with CF?

Answer 46

Bone mineral density (BMD) falls increasing risks of osteoporosis

Question 47

What are some of the treatment options for patients with osteoporosis and CF?

Answer 47

Bone protection drugs, weight bearing exercise

Question 48

What may happen in the lungs of those with CF?

Answer 48

Pneumothorax

Question 49

Why may there by haemoptysis in CF?

Answer 49

Bronchial wall destruction may cause patients to cough up blood

Question 50

What do modulator drugs do in those with CF?

Answer 50

Address different parts of CFTR production, processing, folding, transport and insertion into the membrane.

Question 51

What are the benefits in modulator drugs in those with CF?

Answer 51

Small benefits in lung function. More significant benefit is fall in chest exacerbations, rise in weight and improved QOL.

Question 52

When might you get a double lung transplantation?

Answer 52

Rapidly deteriorating lung function FEV1 < 30% predicted Life threatening exacerbations Estimated survival <2 years Recurrent pneumothorax, recurrent severe haemoptysis

Question 53

List some reasons a patient not be referred for a lung transplant.

Answer 53

Other organ failure Malignancy within 5 years Significant peripheral vascular disease Drug, niotine, alcohol dependency

Question 54

Why have CF survival rates improved?

Answer 54

CF centres MDT teams Physiotherapy Nutrition/Enzymes Antibiotics Aggressive approaches Annual flu/pnemococcal vaccines