Guide

Phenylketonuria is one of the most frequent congenital disorders consisting in decreased metabolism of amino acids. In people suffering from the condition, the body cannot correctly transform one of the proteins: phenylalanine. This makes the protein accumulate abnormally, damaging the brain, which can even lead to profound intellectual disability. Phenylketonuria is accompanied by CNS symptoms such as convulsions and muscle twitching as well as behavioural disorders. People suffering from the disease give off a characteristic musty smell.

Phenylketonuria is a genetic disease occurring when both the mother and the father either suffer from or carry the condition. In such case, the probability of PKU occurring in children is 25% (50% that the child will be born as a carrier of the defective gene). If only one parent has phenylketonuria, the child will definitely be born healthy.

Phenylketonuria is a congenital condition causing irreversible damage to the brain and the nervous system, the extent of which depends on how early the disease is identified. In Poland, newborn babies are tested for phenylketonuria three days after birth and 14 days later. Early diagnosis helps to immediately administer treatment with a correct diet thanks to which the child has high chances to develop normally.

Unfortunately, there is no cure for the disease. The only way to limit its negative consequences for the central nervous system is to follow a strict diet, which prevents body poisoning and brain degeneration. Children must be on the diet until they have completed the phase of intensive development of the brain and the central nervous system (12-14 years of age). Even so, it is recommended that the diet, albeit in a less rigourous version, is followed for the rest of the patient's life. It is specifically important for women who plan to get pregnant or expect a baby. High levels of phenylalanine in the blood is directly related to foetus damage.

In the case of this condition, patients should give up most high-protein foods – meet, fish, eggs, milk and dairy products – as well as bread and product made of flour. Any deficiencies resulting from the lack of such foods in the diet are offset by special supplements that contain properly processed amino acids, vitamins and minerals.

Importantly, a child with PKU must be monitored continuously by a doctor and a dietician who updates the patient's diet on a regular basis depending on nutritional needs and individual preferences. The doctor, on the other hand, determines how much phenylalanine would be safe for the child at a given stage of its development. The level of the protein is determined through regular tests. Children below three years of age are tested once a week, then once every 14 days, and, after they have turned seven, once a month.