Phenylketonuria is a hereditary disease in which the metabolism of aromatic acids lack the enzyme phenylalanine hydroxylase that converts the amino acid phenylalanine to tyrosine. Due to lack of the enzyme phenylalanine accumulates in the body, which is not metabolized. The disease occurs already in births as a hereditary disease and can cause serious physical and psychological harm the child, including mental retardation. It states that if PKU is not treated, can lower intelligence quotient of the child in half.
Therefore, in the Czech Republic fourth to fifth day after birth performed capillary blood from the heel and measure the levels of phenylalanine in the sample. When raised, they will be more tests. If the disease is confirmed, the child should be excluded from the diet phenylalanine. Otherwise, they can come and neurological disorders including epilepsy.
In children with this disease appears characteristic odor like musty because of sweat and urine are excreted as degradation products of phenylalanine. The color of skin, hair and eyes is lighter in affected children than in parents. There are also changes in the skeleton, resulting in a smaller head, lower body and flat feet.
Such disabled children are served a special milk substitutes. After weaning can be kept the substitute, mostly vegetarian diet. The daily need for protein in the diet must be replaced by an artificial mixture of essential amino acids without phenylalanine, which is enriched with trace elements, ions, minerals and vitamins and each depending on the age of the child being treated. They are thus deprived of the protein products of phenylalanine. The need for dietary treatment in individuals with PKU is lifelong.
The diet of patients with phenylketonuria (children, adolescents and adults) are excluded from all protein-rich foods: meat and meat products, milk and dairy products, cereal products, eggs, beans, bread, chocolate and many other foods. The basis for the preparation of patient meals are vegetables, potatoes, fruit, vegetable fats and oils, special flour made from starch to prepare bread, pasta and kept the other products with a low protein content. Fats and sugars can be incorporated without restriction, but must take into account the rational composition of the diet.