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Phenylketonuria (PKU): heel prick screening

About phenylketonuria

Phenylketonuria (PKU) is an inherited condition. It means that a baby's body cannot break down the amino acid phenylalanine, which is found in protein.

This is caused by a problem with a gene, which limits production of the enzyme needed to break down phenylalanine.

High levels of phenylalanine in a baby's body are harmful. If untreated, they can lead to intellectual or physical disability.

Babies born in Ireland with PKU

Around 1 in every 4,500 babies born in Ireland will have PKU or a milder form called hyperphenylalaninaemia.

If both parents carry the altered gene they have a 1 in 4 chance of having a baby with PKU.

How heel prick screening can help

If the heel prick suggests your baby may have PKU, they will be referred to a specialist.

Your baby will be put on a special low-protein diet.

When babies with PKU are diagnosed as newborns and started on treatment, they grow up healthy and well, once the diet is adhered to.

Page last reviewed: 28/11/2018
Next review due: 28/11/2021