Please click on any of the information headers below to expand for an explanation of the terminology used throughout the content on this website.
Newborn screening involves a ‘heel prick’ test. The midwife will collect 4 drops of blood from the baby’s foot on a special card. The blood is then screened for nine rare conditions, including Cystic Fibrosis.
Carriers have one faulty variant of the CFTR gene and one functioning variant. They do not have cystic fibrosis, but have a higher chance (1 in 4) of having a child with cystic fibrosis if they have children with another carrier.
A gene that provides instructions for making a protein called the cystic fibrosis transmembrane conductance regulator (CFTR). This protein helps to maintain the balance of salt and water on many surfaces in the body (e.g. the lungs).
An inherited condition which causes sticky mucus to build up in the body (particularly in the lungs and digestive system). It is a lifelong condition in which symptoms (e.g. struggling to gain weight, frequent chest infections) usually start in early childhood.
This result means that screening showed signs that the baby may be at higher risk of having cystic fibrosis and follow-up tests (such as a sweat test) will be performed to determine whether the baby does have the condition.
This is not a condition or a disease but a way of describing a positive newborn screening result that does not lead to a diagnosis of cystic fibrosis. Most children remain well and healthy, but there is a small chance that a baby may develop cystic fibrosis or a related disorder. The children are monitored by a specialist team.
Limited genetic testing already forms part of newborn screening for cystic fibrosis and looks for the presence of up to 50 of the most common variants associated with cystic fibrosis in the UK. Extended Genetic Testing would instead screen for several hundred variants associated with cystic fibrosis.
A parent is told after newborn screening that their baby has a low chance of having cystic fibrosis when in fact they do have it. Cystic fibrosis has been ‘missed’.
A parent is told after newborn screening that their baby has a high chance of having cystic fibrosis when they do not have it.
Every baby in the UK is offered newborn bloodspot screening, also known as the ‘heel prick’ or Guthrie test. At around five days after birth, the midwife will collect four drops of blood on a card that is screened for nine rare conditions.
IRT is made by the pancreas and is released into the small intestines where it becomes trypsin – an enzyme found in our guts that breaks down the protein we eat so that it can be absorbed. In cystic fibrosis, ducts in the pancreas can become blocked preventing the release of IRT. Screening for cystic fibrosis involves measuring IRT in the blood sample taken from the baby’s heel.
A missed or false negative screening result happens when a parent is told after newborn screening that their baby has a high chance of having cystic fibrosis when, they do not have it.
Screening tests are used to find babies with a higher chance of a health condition. Newborn blood spot screening (the ‘heel prick’ or Guthrie test) is offered at around 5 days after birth.
The result indicates it is unlikely that the baby has cystic fibrosis. The screen was normal and no additional follow-up is required.
Following an initial positive screening result, only one variant linked to cystic fibrosis is found in the genetic testing and there are no other abnormalities identified. Carriers do not have cystic fibrosis, but have a higher chance (1 in 4) of having a child with cystic fibrosis if they have children with another carrier.
Screening tests are used to find babies with a higher chance of a health problem or particular condition. They cannot tell for certain, but indicate the need for follow-up tests.
Sensitivity is the test’s ability to correctly identify a baby with cystic fibrosis.
Specificity is the test’s ability to correctly identify a baby without cystic fibrosis.
One of the tests used to confirm a diagnosis of cystic fibrosis. The sweat test measures the amount of salt in a baby’s sweat. People with cystic fibrosis have a lot of salt in their sweat.
An independent expert group that advises ministers and the NHS, in all 4 UK countries, on which screening programmes to offer. For more information, please see their website by clicking here: UK National Screening Committee
Genetic variants are differences within the genes in our DNA and are responsible for the differences between us, such as having different eye colours. Sometimes variants prevent genes from working properly and these might be referred to as faulty variants.
The process of decoding all of a person’s DNA.