Cystic fibrosis (CF) is a genetic disorder where there is a malfunction in specific genes related to the exocrine system. The exocrine system is responsible for producing saliva, sweat, tears and mucus.
This mutation means that people with CF develop an abnormal amount of excessively thick and sticky mucus within the lungs, airways and digestive system. The mucus causes impairment of the digestive functions of the pancreas and traps bacteria in the lungs which can cause recurrent infections and lead to irreversible damage.
CF mainly affects the lungs and digestive system although respiratory problems, (due to progressive damage of the lungs), are the most common cause of death in people with this disorder.
- Exocrine system: The exocrine system is a system of exocrine glands, such as the saliva glands, which discharge substances out of ducts in the body.
- Pancreas: The pancreas is a long, flat gland that lies in the abdomen behind the stomach. It produces enzymes that are released into the small intestine to help with digestion.
- Autosomal recessive: This is one of several ways that a trait, disorder, or disease can be passed down through families. An autosomal recessive disorder means two copies of an abnormal gene must be present in order for the disease or trait to develop.
- Nebuliser: A device for producing a fine spray of liquid, used for example for inhaling a medicinal drug.
What are the causes?
CF is a genetic autosomal recessive disorder. This means that for a child to be affected, they must acquire one of the genes that cause CF from their mother and one from their father.
Approximately 1 in 25 adults in the population will be carrying the gene but usually they will be unaware they are a carrier because they will not have any symptoms.
Carriers of the genes have a chance of passing it on to the next generation. Two carrier parents have a:
- 25% chance their child will have CF
- 25% chance their child will not have CF or be a carrier of the gene.
They will also have:
- 50% chance of having a child who is a carrier of CF.
This applies to each pregnancy and is unaffected by whether the couple have had an affected or unaffected child previously.
Who is at increased risk?
CF is a genetic disease and cannot be ‘caught’. The only known risk factor is having two parents carrying a gene which causes CF.
How is it diagnosed?
Since 1986, all newborns have been given a heel prick test which is used to screen for CF as well as a number of other conditions.
Diagnosis may also result after a baby is born with obvious CF symptoms such a bowel blockage or failure to 'thrive'.
The heel prick test does not detect everyone and the definitive test for CF continues to be 'The Sweat Test', as a high level of salt in perspiration is extremely common amongst those with CF.
Neonatal screening does occasionally miss a child with CF. Therefore, while it is unlikely that CF is responsible, the condition should still be considered as a possible cause for infants with recurrent chest infections or who do not thrive.
How is it treated?
From birth, a person with CF undergoes constant medical treatments and physiotherapy.
Current therapies focus on improving quality of life and managing symptoms well. These approaches have transformed the life expectancy of people diagnosed with the condition but outcomes are dependent in large part on implementing daily routines aimed at preventing the complications as much as possible and dealing with problems as they arise. They are based on trying to prevent or minimise the progression of the impacts of the condition.
There is currently no cure for cystic fibrosis, though there is some progress towards gene specific therapy.
Management and treatment of CF is life-long. It is important for people with CF to attend a treatment centre from the time of diagnosis. These centres have experienced multi-disciplinary teams who will provide support and advice, and monitor progress.
Treatment generally involves:
- daily physiotherapy to help clear the lungs
- enzyme replacement capsules with food to aid digestion
- antibiotic therapy to treat lung infections
- aerosol mist inhalations via a nebuliser to help open the airways
- salt and vitamin supplements
- a nutritious, high calorie, high salt, high fat diet
- exercise – which is important to help clear the airways and build core strength
- inhaled medications to help breakdown and clear the mucus in the lungs.
Admissions to hospital may be required for intravenous antibiotics if it is not possible to clear an infection with oral antibiotics. Other treatments are available for less common complications which may affect individuals as they get older such as CF related diabetes, liver disease and infertility.
People with CF are not encouraged to socialise with each other in person due to the risk of cross-infection and exacerbation of lung conditions. However, people with CF are able to interact in person with peers without CF. In addition, advances in social media, skype, and online communication platforms are making it easier for people to build support networks and friendships with others who have the condition.
If left untreated
CF is a terminal disease and if left untreated or inadequately managed, can lead to premature death.
How can it be prevented?
Since CF is a genetic disorder, people who inherit the affected genes from both parents cannot prevent the development of the disease. There are more than 1600 genetic mutations that lead to CF, some of which are particular to individual families.
An infant who receives the CF gene from just one parent will not be born with CF, but could be a symptomless carrier of the gene like their parents. The genes responsible for CF must be inherited from both parents and it can skip generations, therefore carriers may be unaware that CF is in their family medical history.
People concerned about CF and thinking of having children may consider carrier screening.
Where to get help
- Cystic fibrosis (CF) is an incurable, genetic disorder.
- It impacts the lungs and digestive system and requires ongoing management by a specialised health care team.
- People living with CF should not socialise in person with others who have CF because of the risk of cross-infection by bacteria in their lungs; these infections can be dangerous for people with CF.
- It is important that people with CF have high quality social and emotional supports as well as support to meet their physical and medical care needs.
Cystic Fibrosis WA
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