Phenylketonuria (PKU) is an inherited autosomal recessive metabolic disease. Its cause is the absence or insufficient level of PAH (phenylalanine hydroxylase) activity. This enzyme is involved in the conversion of the amino acid phenylalanine to tyrosine in the liver. When this is disrupted, phenylalanine accumulates too much in the body. Phenylketonuria – causes The gene encoding PAH is located on chromosome 12. In order for a child to get sick, he must inherit an abnormal gene from both parents. People who have 1 allele with the mutation are carriers and have no symptoms, but they can pass the defective gene on to their offspring. If both parents suffer from phenylketonuria, all children will also have the disease. With 2 carriers, the risk is as follows: 25% sick child, 50% carrier child, 25% healthy child. If one of the parents is a carrier of the mutation, the probability that their child will also be a carrier is 50%. Phenylalanine, as an essential amino acid, cannot be synthesized by humans, it must come from food. Phenylalanine is a precursor of tyrosine, which is necessary for the production of various neurotransmitters (dopamine, serotonin), hormones (thyroxine, adrenaline, norepinephrine) and melanin. Symptoms Since 1986, screening tests for newborns for phenylketonuria have been introduced in Europe, covering the entire newborn population. Then the level of phenylalanine in the child's blood is checked. If it is 2.5 mg / dl, the amino acid concentration is checked again to exclude a temporary increase in phenylalanine, for example, in case of liver failure or enzymatic immaturity of the newborn. If the result is abnormal again (3 mg/dl MS/MS), further tests are performed, including molecular (PAH gene mutation detection). According to the level of hyperphenylalaninemia, the following forms can be distinguished: • severe form of PKU (so-called classical)> 20 mg/ dl, • mild form of PKU – 10-20 mg / dl, • mild hyperphenylalaninemia – 6-10 mg / dl, treatment is required for patients under 12 years of age and pregnant women, • hyperphenylalaninemia below 6 mg / dl is the mildest form that does not require dieting. Symptoms of phenylketonuria occur as a result of the toxic effect of phenylalanine and its metabolites on the nervous system, which leads to delayed psychomotor development and decreased intelligence, seizures, microcephaly, and muscle tension disorders – these damages are usually irreversible. There may also be vomiting, skin rashes similar to allergic ones, and due to a violation of the production of melanin (pigment), the patient may have fair skin and hair, blue eyes. The smell of urine is also characteristic – it is caused by phenylacetic acid, a metabolite of phenylalanine. Phenylketonuria – treatment Treatment of phenylketonuria includes dietary restriction of phenylalanine and tyrosine supplementation and should be continued throughout life. What should a diet look like for phenylketonuria? Phenylketonuria – diet Patients with phenylketonuria require a diet low in phenylalanine and adequate calorie intake. According to European recommendations, it is recommended to increase the protein content moderately (the exact values of the daily protein allowance, taking into account the age of the child, can be found in the recommendations of the phenylketonuria group). Special drugs for the treatment of phenylketonuria are available for patients, containing free amino acids, which provide about 80-85% of protein, and tyrosine. They not only help to reduce the level of phenylalanine in the blood, but also increase its nutritional tolerance. Foods rich in phenylalanine: legumes, seeds, milk, meat (including poultry, fish), flour, cereals, cocoa, chocolate, gelatin, aspartame. Fruits and vegetables with a phenylalanine content of 75 mg / 100 mg of the product are allowed in the patient's diet: tangerine, mango, apple, cherry, strawberry, peaches, apricots, tomatoes, radishes, celery, cucumbers. Due to a strict diet and the exclusion of a large number of natural protein sources, vitamin (including B12) and mineral supplements may be required. Dietary control in a pregnant woman suffering from phenylketonuria allows her to give birth to a healthy baby. As for the diet of an infant suffering from phenylketonuria, breastfeeding is allowed, but in a strictly defined amount (human milk contains 46 mg of phenylalanine per 100 ml of milk). The situation is similar with standard formulas. Официальное приложение Мелбет для iPhone доступно жителям Новосибирска по ссылке Мелбет скачать на айфон . Установите его и получите доступ к ставкам на футбол, хоккей, теннис и киберспорт. Промокод на бонус активируется в личном кабинете сразу после регистрации. Горячая линия: 8 (800) 310-77-77.
