June 30, 2007



Cystic fibrosis (CF) is a common, genetic (inherited) disease that affects about one in every 3000 babies born. In people with CF, the secretions produced by various glands in the body are thicker and stickier than normal. Usually the respiratory and digestive systems are most affected, but other problems such as osteoporosis (brittle bones) may also occur.

Screening and diagnosis
All babies born in Australia are tested for CF as part of the routine day 4 bloodspot test. This test determines the concentration in the blood of a certain chemical made by the baby’s pancreas. If a high concentration of this chemical is found, then the same blood sample is tested for genes commonly associated with CF. However, while newborn screening has improved the early detection of CF, up to 10 per cent of cases will not be picked up.

Babies with CF may develop a bowel obstruction (meconium ileus) in the first few days of life. In babies who are not diagnosed early with CF, the first signs of the disease are often failure to thrive (where they don’t gain weight normally) and/or recurrent chest infections.

A sweat test (which measures the amount of chloride in the sweat) is used to make the diagnosis of CF.

What problems does CF cause?
Children with CF tend to have recurrent chest infections and breathing problems. As children get older, their lungs may become permanently damaged.

Because the pancreas doesn’t produce the usual enzymes and secretions necessary for digestion, people with CF can have problems with malnutrition. Also, about 40 per cent of people with CF will develop problems with their liver, and 5-10 per cent will develop diabetes.

What treatments are available?
Unfortunately, there is no cure for CF, but there are treatments available to help correct the nutritional problems and prevent and treat respiratory infections.

Most people with CF have to take pancreatic enzyme replacement capsules to aid digestion and correct nutritional deficiencies. People with CF are also encouraged to use antibiotics for chest and sinus infections, and new medications are now available to reduce the stickiness of the sputum in the lungs.

Lung and liver transplants are now being performed in more severe cases.

How is CF inherited?
To have cystic fibrosis, you need to have 2 genes for the disease (one from each parent). It is much more common to have just one CF gene — these people, so-called ‘asymptomatic carriers’ do not have the disease or any symptoms.

If a healthy couple each carry a CF gene, with each pregnancy there is a one in 4 chance they will have a child with CF; a 2 in 4 chance the child will be an asymptomatic carrier; and a one in 4 chance the child will neither have CF nor be a carrier.

myDr 2006