What is Phenylketonuria (PKU)?

Phenylketonuria (PKU), pronounced as fee-nile-key-tone-you-ree-ah, is a rare but treatable inherited disorder that prevents the normal breakdown of protein.

Babies with PKU inherit two faulty copies of the gene for PKU, one from each parent.  When we eat, our body breaks down protein in food into smaller parts called amino acids. Special chemicals found naturally in our body, called enzymes, then make changes to the amino acids so our body can use them.

If a baby has PKU, one of these amino acids called phenylalanine (fee-nile-al-an-een) does not break down in the usual way and builds up in the blood.  Without early diagnosis and treatment, PKU can lead to long term health problems including learning difficulties.

 

Symptoms

If the right treatment is followed, babies with PKU are well in early life and do not develop symptoms.

Without early treatment babies can develop damage to the brain, including learning difficulties.

 

Treatment

Treatment for PKU involves a special low-phenylalanine diet. The aim of the diet is to reduce the build-up of phenylalanine which can cause learning difficulties and brain injury.

As high protein foods and milk (including breast milk and normal infant formula) have to be limited, a special infant formula is given to meet all nutritional requirements. This special infant formula is very important because it allows normal growth and development as well as helping to reduce the build-up of harmful toxins in the brain.

Your specialist metabolic dietitian will teach you how to measure and control the amount of protein you give to your baby, including breast milk feeds.

Your baby will need regular blood tests to monitor phenylalanine levels in their blood.

Babies with PKU benefit significantly from effective treatment and can live healthy and active lives

 

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