What is cystic fibrosis?
Cystic fibrosis is a serious, lifelong inherited condition, which predominantly affects the lungs and digestive system but can also affect other organs, including the liver and reproductive organs. Cystic fibrosis affects more than 8,500 people in the UK and five babies are born with the disease every week. Cystic fibrosis is one of the most widespread critical conditions that are inherent.
How does cystic fibrosis affect the body?
Cystic fibrosis causes mucus to clog up the tubes and ducts in the body, preventing them from working properly. The faulty genes that cause cystic fibrosis prevent the body from controlling the passage of salt and water into the cells. The disease creates too much salt and not enough water to pass through the cells, which causes sticky mucus to develop in the passageways. When the tubes and ducts in the lungs are clogged, it makes it difficult to breathe and increases the risk of infections. When the tubes in the digestive system are blocked, this causes difficulty with digesting food.
What causes cystic fibrosis?
Cystic fibrosis is a genetic condition caused by a faulty gene on chromosome 7, which is inherited from both parents. Cystic fibrosis is a recessive condition, meaning that the faulty gene must be inherited from both parents for a child to have the condition. It is possible to be a carrier of the condition without suffering from the disease, and you will be a carrier of cystic fibrosis if you inherit one gene instead of two. It is estimated that around 1 in 25 people are carriers of the faulty gene that causes cystic fibrosis.
How is cystic fibrosis inherited?
Cystic fibrosis is a recessive condition, which means that the faulty gene must be passed on by both parents in order for their child to suffer from the condition. If only one gene is passed on, the child will be a carrier.
If two carriers of cystic fibrosis have a baby, the following outcomes are possible:
- There is a 1 in 4 probability that the child will not inherit faulty genes, which means they will not be a carrier or suffer from the disease.
- There is a 1 in 2 probability that the child will inherit one faulty gene, which means that the child will be a carrier of cystic fibrosis but will not suffer from the disease (but they can pass on the gene to their child).
- There is a 1 in 4 probability that the child will inherit both copies of the faulty gene and will therefore suffer from cystic fibrosis.
What are the symptoms of cystic fibrosis?
Symptoms for cystic fibrosis tend to develop during the first year of a baby’s life. Most commonly, the disease affects the lungs but it can also hinder the normal function of other organs. Symptoms cannot be cured, but they can be eased using medication and other treatments, such as physiotherapy. Cystic fibrosis affects people in different ways and some people have much more severe symptoms than others.
Symptoms affecting the lungs:
- Coughing (the body coughs to try and dislodge the mucus from the lungs).
- Frequent chest infections: this is due to the build-up of mucus, which is a breeding ground for bacteria.
- Lung infections: cystic fibrosis sufferers are prone to lung infections, caused by two strains of bacteria known as Pseudomonas aeruginosa and Burkholderia cepacia complex. The infections are not usually harmful for people who do not have CF, but if they pass on an infection to somebody with CF, this can cause them to develop symptoms.
Symptoms affecting the digestive system
Often, cystic fibrosis affects the pancreas. The pancreas secretes enzymes, which are used to digest food. If the pancreas is not working properly, food cannot be digested properly and this can result in the following symptoms:
- Large, unpleasant smelling stools: this is because food is not digested fully.
- Malnutrition, which makes it difficult to gain weight, even if you have a healthy appetite.
- Diabetes: this usually occurs in older people and is caused by damage to the pancreas, which makes it more difficult for the body to control blood sugar levels.
Cystic fibrosis mainly impacts the function of the lungs and pancreas, but it can also affect other parts of the body. Symptoms may include:
- Hay fever.
- Nasal polyps.
- Increased risk of osteoporosis.
- Joint pain.
- Increased risk of fractures.
- Impinged liver function and liver damage, which may lead to cirrhosis.
How is cystic fibrosis diagnosed?
Various tests may be carried out to confirm a diagnosis of cystic fibrosis. These include:
- Sweat test: a sweat test measures the amount of salt in sweat from the skin. If the level of salt is abnormally high, this indicates cystic fibrosis.
- Genetic test: genetic tests can confirm the diagnosis and samples can be taken from the inside of the cheek or a blood sample may be taken.
- Screening test: newborn babies in the UK are screened for cystic fibrosis and a heel prick test is usually carried out at the age of 6 days. The screening test is used to test for high levels of a chemical called immunoreactive trypsinogen. If the test shows a high level, a sweat test and genetic tests will be carried out.
Treatment for cystic fibrosis
There is no cure for cystic fibrosis but there are treatments available to prevent or ease symptoms. Children who are diagnosed with cystic fibrosis are referred to a multi-disciplinary team, which is made up of paediatricians, specialist nurses, dieticians, counsellors and physiotherapists.
Treatment options for cystic fibrosis include:
- Medication for the lungs: antibiotics are commonly provided for children and adults with CF because they are prone to infections. Babies usually take antibiotics continually until the age of 3. Antibiotics can be taken in tablet form or inhaled. Steroids can also be taken to reduce inflammation of the airways, which makes it easier to breathe. Bronchodilator drugs help to open the airways and make breathing easier.
- Digestive system medication: enzyme supplements are taken to aid digestion and fat-soluble vitamin supplements may also be used to replace lost vitamins. Insulin will also be needed by patients who develop diabetes, as this helps to keep blood sugar levels stable.
- Exercise and physiotherapy: exercise is beneficial for general health, as well as for CF. Chest physiotherapy is very important. People with CF attend regular appointments with a physiotherapist, as physiotherapy helps to clear the airways and make it easier for people to breathe. Often, twice daily sessions are recommended and this may be increased if an individual has a chest infection.
Research into treatment options for cystic fibrosis is ongoing and new treatments, including gene therapy and new drugs, could be made available in the future.
What is the outlook for cystic fibrosis?
There is no cure for cystic fibrosis and it is a serious condition; however, the prognosis has improved in recent years and people are living for longer. In the 1960’s babies born with CF usually only lived for months, but now many people are living into their 30’s and it is estimated that 8 out of 10 children born with the disease now will live into their 40’s. Treatments are usually effective in controlling symptoms and many people live a healthy and fulfilling life. However, there is an increased risk of infection and this can cause people to fall ill very quickly and it is not uncommon for children and young adults to die from the disease. Research into treatments is ongoing and it is hoped that life expectancy will continue to increase.