Family doctor

Cystic Fibrosis (CF) is a genetically inherited condition that affects the way salt moves in and out of cells in the body. This has important effects on lung and digestive systems .

 Many millions of people worldwide carry the defective CF gene and do not have symptoms, this is because for a person to be affected by CF they need to have inherited a defective CF gene from both parents.

Approximately one in every 2500 babies born in New Zealand are affected by CF.

How is CF diagnosed?

People are usually diagnosed with CF soon after birth as it is one of the conditions screened for by the Guthrie test (the heel-prick blood test taken when a baby is a few days old). The heel-prick blood is tested for the presence of a high level of a pancreatic enzyme known as immunoreactive trypsinogen and if detected then another sample from the Guthrie test card will be used to test for the most common gene mutations causing CF. In addition a sweat chloride test is performed which reveals a high salt level in the sweat if the baby has CF.

If a baby does not have the Guthrie test performed and happens to affected by CF, then it might not diagnosed for several years. These late diagnoses tend to happen when a CF test is requested as part of investigations that may occur when evaluating a child with failure to thrive, poor growth or chronic ill health of a respiratory or gastrointestinal nature.

It is considered an advantage for a person to discover they have CF soon after birth so that the CF can be appropriately managed as soon as possible which helps add to improved survival and quality of life.

How does CF affect the body?

The faulty salt movement caused by CF causes changes to the water balance in cells which in turn leads to the body producing abnormally thick mucus affecting the function of the lungs and digestive system. In addition the majority of males with CF will be infertile.

CF is a condition that may lead to serious respiratory problems in childhood and young adult life. However survival rates have improved dramatically over recent decades, and it is now thought that children born in the 21^st century will have an average life span of over 50 years.

It is important to try and be cared for in a unit with specialist expertise in cystic fibrosis as outcomes can vary greatly depending on care.

Management of CF

Generally a person with CF requires intensive care and treatment of their lungs and digestive system.

Treatment for lung problems include:

·         Lung physiotherapy (airway clearance techniques) and exercise to help loosen and cough up mucus

·         Avoidance of second-hand smoke, and counselling people with CF to never smoke themselves

·         Antibiotics are often needed to treat lung infections that can be frequent. Sometimes people with CF may also be on preventative treatment with antibiotics.

·         Inhaled medicines to help open the airways

·         Flu vaccine yearly

·         Pneumococcal vaccine

·         Oxygen therapy may be needed in some cases

·         Lung transplant is an option in some cases

Treatment for digestive problems include:

·         A high-protein, high-calorie diet

·         Vitamin supplements especially the fat soluble vitamins A,D and E

·         Pancreatic enzymes to help the intestine absorb fat and protein better

What are my chances of having a baby with CF?

If someone in your family has CF, then family members can be tested to find out if they are carriers of the faulty CF gene.

Whether you are a man or a woman, if you are not a carrier of this gene then you are not able to have a child with CF. If you are found to be a carrier of this gene, then it is only if you have a child with someone who also is a carrier of this gene, that you then have a 25% chance of having a child affected by CF.

Carrier testing: A blood test or a swab taken from the inside of the cheek are both ways of having your carrier status checked. This can be arranged through your GP. Couples who are at increased risk of having a child with CF (i.e. they are both carriers for the faulty gene) can be referred to genetic services to discuss options such as pre-implantation genetic diagnosis.

Supportive networks available for people with CF and their families

The Cystic Fibrosis Association of New Zealand is an organisation that can give information and appropriate support to people living in with CF and their families.

http://www.cfnz.org.nz/