Cystic Fibrosis

Cystic fibrosis (CF) is a disease that affects many functions of the body including breathing, digestion and reproduction. In CF, the glands that produce mucus, saliva, and intestinal fluids do not work properly. Thick, sticky secretions build up in the lungs and digestive tract. These cause symptoms such as:

• coughing/wheezing
• chest infections
• poor digestion and persistant diarrhoea
• slow growth

	What is the cause of cystic fibrosis?

Cystic fibrosis is a recessive genetic condition. This means that the faulty gene must be inherited from both parents in order for a child to develop the condition. CF is the commonest single gene condition among white Europeans. Approximately one in 25 people has one copy of the gene: they are carriers of CF. Carriers are not affected by the condition. Approximately one in 600 British couples are both carriers of the CF gene. If two carriers of the CF gene have a child together, there is a one in four chance of that child inheriting the affected gene from both parents, and therefore being affected by the condition. Approximately one in every 2000 babies born in Britain has CF.

Early detection of CF is important, because early treatment can be beneficial. However, unless the parents know they are carriers, there may be no indication that a baby has the condition, and symptoms may not be evident for months or even years. A good indicator of a baby having Cystic Fibrosis is that they tend to taste salty if you lick them, and while this is not always accurate, it can tell parents that there might be something wrong with their child. A "sweat test" performed in hospitals measures chloride more accurately, which will detect the condition.

Because CF is an inherited condition, there is a 25% chance that future pregnancies will also be affected. If the parents know they are carriers, either because they have been tested, or because they have already had a baby with CF, they may be able to have tests in pregnancy to detect whether their unborn child has the condition. In this case, they would be offered a termination of pregnancy. Alternatively, they may be offered pre-implantation genetic diagnosis, a new technology in which embryos are created with the parents' eggs and sperm in vitro, and the embryos are tested to see if they are free of the genetic mutation. Only unaffected embryos are implanted, and if the pregnancy is successful, it should result in a healthy baby.

	How does cystic fibrosis affect people?

CF does not affect a person's intelligence. Children with CF look like any other children, although they may be smaller than average for their age. They can walk, attend normal schools, go to college, and live and work independently. However, illness may cause children and adults with CF to miss out on schooling or work, and the need for regular physiotherapy may disrupt their day. CF may cause embarrassment to a child - because of being smaller than average, or coughing up mucus. Most people with CF experience support and understanding from others.

While CF is usually diagnosed in childhood, people with mild symptoms may not be diagnosed until they are older. CF often becomes worse with age. Many people with CF are expected live into their mid-30s.

	Health complications in cystic fibrosis.

Adults with CF may develop diabetes and osteoporosis. In rare cases, CF can cause the blockage of small ducts in the liver. This only happens to approximately 8% of people who have CF. However, this is a serious health risk and may necessitate a liver transplant.

Although CF does not cause sexual impotency it can lead to fertility problems. In most men with CF, the tubes that carry sperm are blocked, which causes infertility. Because underweight women are more likely to have irregular menstrual cycles, the nutritional problems associated with CF may affect fertility. However, women with CF do produce healthy, fertile eggs so effective contraception is necessary

	Treatments available for cystic fibrosis.

Physiotherapy is used to clear the thick, sticky mucus from the lungs. This helps reduce infection and prevent lung damage. Parents are taught how to do this for their child by the physiotherapist in the CF clinic. Adults with CF can learn how to administer their own physiotherapy. A physio session might take 10 minutes, or up to an hour, and be repeated twice a day, or up to four times a day when necessary.

Various medications are available to help with breathing and digestive problems. These work by opening up airways (bronchodilator drugs) or controlling infections (antibiotics) or reducing inflammation (steroids) or break down mucus (Dnase). Enzyme pills should be taken with meals and snacks to replace pancreatic enzymes and enable people with CF to gain more energy from food. Nutritional supplements may also be valuable.

Lung transplants for people with CF have an encouraging success rate: 70% survive one or two years after transplantation and the longest surviving patients had their transplant operation 12 years ago. Like any other major surgery it carries considerable risks and is appropriate only for a patient who is severely ill and has tried all other forms of conventional treatment. To these patients, lung transplantation offers a better quality of life.

Who can I contact for more information?

Cystic Fibrosis Trust:
http://www.cftrust.org.uk
Cystic Fibrosis Resource Centre:
http://www.cysticfibrosis.co.uk/