What Is PKU?

PKU (Phenylketonuria) is a metabolic disorder which affects the enzyme that digests an amino acid called phenylalanine into another amino acid, tyrosine. Treatment includes maintaining a low-protein diet (phenylalanine is found in protein) and drinking a special formula that contains tyrosine, as well as the nutrients in protein that are lost due to the low-protein diet. PKU is a recessive gene, which means that you must acquire both genes from your parents to be affected by it (see image at right).
  Image by Anesu Venge
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