Cystic fibrosis develops because of a faulty gene – known as the CFTR gene - which stops salt moving in and out of cells effectively, causing an increased production of mucus.
Symptoms include breathing problems (involving wheezing and shortness of breath) and recurrent lung infections, such as pneumonia, and coughing up sputum is also common. The build-up of mucus in the lungs also blocks the flow of digestive juices from the pancreas which can result in food not being broken down and absorbed properly.
Frequent diarrhoea is often a symptom. For this reason, children with the condition generally struggle to put on weight or grow at the expected rate and boys born with CF often suffer fertility problems (the tube carrying sperm from their testes to the penis can be blocked).
People with cystic fibrosis commonly also develop a number of related conditions including diabetes, osteoporosis (weakened bones, linked to poor absorption of nutrients, particularly vitamin D) and liver problems.
In the UK, all babies are tested for CF at around 6 to 10 days with a heel-prick blood test to detect a chemical called immunoreactive trypsinogen (levels are high in babies with CF).
Further tests include the sweat test, which involves collecting enough sweat from your baby to measure their levels of chloride, a component of salt. Kids with cystic fibrosis have two to five times more salt in their sweat than those without the condition and the sweat test is said to be the most reliable diagnostic tool.
A genetic test may also be done, either by scraping cells from the inside of the cheek for testing or via a blood test. If your child is diagnosed with cystic fibrosis, any siblings should also be tested and if a member of your family gets a cystic fibrosis diagnosis, you should take a genetic test as there is a chance you could be a carrier. Some cases of cystic fibrosis are diagnosed in adulthood, but these generally have mild symptoms.
Who gets cystic fibrosis?
Both parents must carry the cystic fibrosis gene for their child to be affected. A child where both parents are carriers of the faulty gene has a one in four chance of having the condition, a two in four chance of being a carrier and a one in four chance of having neither cystic fibrosis or being a carrier of the faulty gene.
One in 25 people of people in the UK of white European descent (Caucasian) carry the gene – usually without knowing. It is less common in Afro-Caribbean and Asian people.
Cystic fibrosis sufferers need regular checks and tests to monitor their condition. Treatments include daily manual chest physiotherapy to clear the airways of the thick mucus.
This involves postural drainage – placing the body in a position which allows to mucus to drain from the smaller airways to the main airway and percussion or vibration therapy - ‘clapping’ the chest firmly with a cupped hand and vibrating it to loosen mucus in the lungs.
A range of drugs may be recommended, including a mucus-loosening and thinning one called Pulmozyme, but can also include antibiotics, bronchodilators (to help open the airways), hydrators (to moisten the thick mucus) and CFTR modulators to help keep a balance of salt and water in the lungs.
Most people with cystic fibrosis will take enzyme supplements to help them digest food more effectively, with some cystic fibrosis patients taking up to 50 tablets a day.