Since 2007, Newborn screening has helped to make an early diagnosis of CF. Most new cases of CF are identified in this way. This uses the routine screening for lots of conditions in newborn babies using the heelprick blood spot tests at Day 6 of life. The test measures Immunoreactive trypsinogen (IRT) levels in the blood. Samples with high IRT levels will go for CF gene mutation screening so results can take up to 4 weeks to come through and sometimes a second heelprick test is needed. Any positive result is notified to your nearest CF centre.
Have a look at the flow chart below for more information.
To have CF, you need to have two CF causing genes, one from your mother and one from your father. CF genes (mutations) code for the production of a protein called CFTR ( Cystic Fibrosis transmembrane regulator) in body cells. CFTR allows salt (Chloride) and with it water to pass across cells. CFTR does not work properly in people with cystic fibrosis and exactly why it doesn’t work is decided by the exact CF gene mutation combination you have (called your Genotype). Lots of exciting new drugs are targeted straight at the CFTR abnormality – see the section on novel therapies in the CF Trust link.
If your baby has a positive screen, the CF Nurse Specialist will liaise with your Health Visitor to discuss the result and arrange a joint visit to your home to explain the result and what needs to happen next. The diagnosis of CF will need to be confirmed, so an appointment with a CF specialist consultant will be made soon afterwards and some further tests will be arranged. These include a blood test (to confirm the screen result), a stool (poo) test, to find out how well your baby’s digestive system is working, and at a later date a sweat test.
We now know there are different types of CF which range in severity. Identifying the specific CF genes can help us understand more about your baby’s CF and some of the newer treatments are matched to specific CF genes.
Sometimes there can be uncertainty after screening and this can be frustrating for parents. These babies are termed CF screen positive, inconclusive diagnosis (CFSPID) and we advise that they are followed in our clinics in order to ensure the baby remains well. If this is the case for your child we will support you with this uncertainty and pull together all the information from follow up tests to help you understand the information available for your child.
National Screening Algorithm
Outcomes are predicted for a population of 10,000 newborn