Cystic fibrosis is a hereditary disease that is transmitted by recessive genes, so that both parents need to be carrying the gene before a child will suffer from it. The incidence varies from country to country and race to race. In the United Kingdom about one child in every 250,000 is born with it. In most peoples of Northern European extraction the gene is carried by about 3 per cent of the population. The basic problem that cystic fibrosis induces is mucus, which is produced by many different glands, including those of the pancreas and the ones found in the bronchial tubes and in parts of the intestines and the reproductive organs.

The principal troubles that a child is likely to suffer is that the mucus produced in the bronchial tubes is so sticky and excessive that it blocks the airways and as a result these become prone to recurrent infection, including pneumonia and severe bronchitis.

If the problem hasn’t been picked up at birth — by symptoms such as poor behaviour of the baby’s intestine, which is likely to suffer a blockage — it is usually diagnosed at under a year because of recurrent chest infections. The amount of salt in the sweat is also a characteristic of cystic fibrosis — the sweat of children with the condition is rich in sodium. Diagnosis is by a blood test, sweat analysis to measure the amount of sodium, and x-ray studies.

Treatment is with postural drainage, to make certain that the lungs are draining properly, and anti-biotics to treat any infection.

The method of giving the anti-biotic is constantly changing and improving. The improved prognosis is largely because of better anti-biotics and better methods of delivery. Mucolytics — medication that makes the mucus less sticky — is another aid. Damage to the pancreas may require specific treatment with digestive enzymes. Once the children reach adult life a small percentage will go on to develop insulin-dependent diabetes, which will need the appropriate therapy.

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