Neonatal screening test targets
What is being screened for?
Newborn screening helps to identify a range of conditions, including:
- Phenylketonuria (PKU) — PKU is a rare condition that affects about 1 in 10,000 babies. A baby with this problem cannot properly use one of the building blocks of protein called phenylalanine, which accumulates in the blood and causes brain damage. This is a rare inherited condition that can cause severe learning difficulties. Early treatment with a special diet can prevent disability and allow babies to lead a normal life.
- Congenital hypothyroidism (CHT) — Hypothyroidism affects about 1 in 3,500 babies. It is caused by the thyroid gland not developing properly. Early treatment with daily thyroid hormone leads to normal mental and physical development.
- Cystic fibrosis (CF) — 1 in every 2,500 babies has cystic fibrosis. In cystic fibrosis, the mucus produced in the intestines and lungs is thicker than normal. This results in infections in the lungs. In the intestines, it may lead to difficulties with digesting food properly. The newborn screening test detects about 95% of babies with CF but also detects a few babies who are healthy carriers of CF. Babies with a positive test result will need a sweat test at about 6 weeks of age to determine whether the baby has CF or is only a healthy carrier. A healthy carrier is not affected with CF and their body functions normally.
- Galactosaemia — An extremely rare disorder only affecting 1 in 40,000 babies. The disorder is caused by the accumulation of galactose (a type of sugar in milk) in the blood. Prompt treatment with special galactose-free milk will prevent serious illness. Without treatment, a baby may become very sick and die.
- Other rare disorders of metabolism — The blood tested in the heel prick test can be tested for a range of other very rare metabolic disorders such as such as amino acid, organic acid and fatty acid oxidation defects. Collectively these disorders occur in 1 of every 4,000 babies and so are rare. These conditions are often treatable with specialised care and diets.