People who have CF produce a thick sticky mucus which both clogs the tiny airways in the lungs and blocks digestive glands preventing their body's natural enzymes from breaking down food. They are prone to constant chest infections and mainutrition.
About one in every 2,500 babies is born with Cystic Fibrosis.
The way in which our bodies develop is determined by pairs of genes. We inherit one gene of each pair from our mother, and the other from our father; which ones, being determined entirely by chance.
About one-in-25 of the population is a carrier of the faulty gene which can cause CF in their children. CF carriers are completely healthy because they also have one normal gene which overrides the defective "CF gene.
If both parents are carriers of a defective "CF gene", any child they have stands a one-in- four chance of having CF (if they inherit a defective gene from each parent); a one-in-two chance of being completely healthy but a carrier (having inherited a faulty gene from one parent and the normal gene from the other); and a one-in-four chance of being total]y unaffected (having inherited normal genes from both parents).
In 1989 scientists discovered the faulty gene which causes CF and it is now possible to offer prospective parents a simple mouthwash test - or "screen" - to see if they are carriers. Specialist genetic counselling is also available for couples who both carry the gene to help them understand the chance of their having a baby with the disease, and also to explain decisions they will have to make before a pregnancy.
Screening is particularly important for people who are either related to someone with CF or a known CF carrier because they are more likely to carry the gene. Their partners should also be tested.
As yet there is no cure for Cystic Fibrosis. However, better treatments can help people with CF to control their symptoms and lead active and fulfilling lives:
Daily physiotherapy to help prevent excessive build-up of mucus in the lungs. Parents learn techniques early on and children are encouraged to be active and take responsibility for their own physiotherapy and breathing exercises.
Inhaled drugs including antibiotics control recurring chest infections.
High energy foods, usually supplemented by enzyme tablets to help break down foods and combat digestive difflculties.
A mucus-thinning drug to help clear the lungs has recently been launched and there is promising research in the field of gene therapy.