All About PKU

PKU is the shorthand name for a condition known as Phenylketonuria or Folling’s Disease. PKU occurs when an excess of phenylalanine (an essential amino acid that is a building block of protein) builds up in the body because the enzyme responsible for processing it is absent.

In the past, medical professionals knew little about PKU and mental retardation and neurological handicaps could result in children left untreated.

Today, PKU is treatable and babies diagnosed with PKU have every chance of growing into healthy adults.

What Causes PKU?

PKU occurs in babies when a biochemical abnormality is inherited from both parents. If both parents are carriers of this trait, there is a 25% (one in four) chance that their child will be born with PKU. In the UK, the incidence of PKU is one in every 12,000 births or about 75 births per year.

How is PKU Diagnosed?

Throughout the UK there is a national screening program for PKU. In the first month of life, a heelprick blood test is taken from infants.

Processes such as chromatography, fluorometry and mass spectrometry are then used to measure the phenylalanine levels in the sample. An excess of phenylalanine indicates PKU.

How is PKU Treated?

PKU is treated via a special diet aimed at lowering phenylalanine levels in the body. To this end, foods high in protein are avoided, including:

  • Meat
  • Fish
  • Poultry
  • Eggs
  • Milk
  • Cheese
  • Breads
  • Cereals
  • Biscuits
  • Pasta

Rather than eating these high protein foods, babies and children diagnosed with PKU can consume alternatives enriched with protein substitutes.

In the first few days after diagnosis, babies will be given a special low phenylalanine formula for a few days until their phenylalanine levels even out.

After that, medical professionals will advise the amount of breast milk or bottle milk to be given.

What Foods Can Children with PKU Eat?

Babies with PKU can begin eating solid foods at the same time as any other baby, around the 6 month mark.

At this time all fruits and most vegetables (including those in packaged baby food) can be eaten. When more solids are introduced, many special, low protein foods will be available on prescription from the chemist, including:

  • Breads
  • Biscuits
  • Pastas
  • Cereals
  • Protein mix

How Long Must the PKU Diet Be Followed?

It was once thought that when children became teenagers, they could relax their low phenylalanine diet and begin to consume more mainstream foods.

However, recent developments have found that even teenagers who relax their diets may suffer from brain abnormalities when they grow into adulthood.

To this end, it is now thought that those suffering from PKU will need to follow a restricted diet throughout their lives and any relaxation to their diet should be made only with the approval of medical professionals.

Further Information on PKU

Many organisations exist across the UK to inform and support sufferers of PKU and their families. For more information, try searching the internet.

PKU can be hard on families and children, but with the right diagnosis and a strict diet, this condition should make little difference to your child’s life and development.

Keep in touch with your GP or specialist and there is little reason a child with PKU should lead a life unlike anyone else!

See Also
Sliced bread
Gluten Free
Guide to Vitamins