Phenylketonuria  (PKU) is a rare genetic condition that causes an amino acid called phenylalanine to build up in the body


  • Intellectual disability
  • Delayed development
  • Behavioral, emotional and social problems
  • Psychiatric disorders
  • Neurological problems that may include seizures
  • Hyperactivity
  • Poor bone strength
  • Skin rashes (eczema)
  • A musty odor in the child’s breath, skin or urine
  • Fair skin and blue eyes
  • Abnormally small head (microcephaly)


  • Genetic mutation
  • Autosomal recessive mutation

Risk factors

  • Having two parents with a defective PKU gene
  • Being of certain ethnic decent

Diagnostic Test

  • Blood tests
  • Urine Tests
  • Genetic tests


  • Low protein diet
  • Dietary supplements
  • PKU medication
  • Avoid high protein diet:
  • Red meat
  • Eggs
  • fish
  • cheese
  • nuts and seeds
  • flour-based foods – such as bread, cakes and biscuits
  • Quorn and tofu
  • Aspartame:
  • sugar substitutes – such as artificial sweeteners often used in tea and coffee
  • diet versions of fizzy drinks
  • chewing gum
  • squashes and cordials
  • some alcopops

Lifestyle management

  • Keep track and measure correctly
  • Buy low-protein products