Fenilketonuriya

Short characteristic of a disease

Fenilketonuriya is a hereditary disease which is characterized by disturbance of protein metabolism.

For the first time this disease was found in 1934. Fenilketonuriya is inherited on type so-called autosomal recessively, that is at absolutely healthy parents (carriers) children sick with a fenilketonuriya can be born.

Types of a fenilketonuriya

There are 3 types of this disease.

Fenilketonuriya of the first type – is characterized by deficit in an organism of enzyme of a phenylalanine-4-hydroxylases. Thanks to this enzyme amino acid phenylalanine turns into tyrosine. The fenilketonuriya of this type is most often inherited (in 98% of cases).

Fenilketonuriya of the second type – is characterized by a lack of such enzyme as dihydropteridinereductase. Patients with a fenilketonuriya of the second type have spasms and mental retardation. This type of a fenilketonuriya occurs at children quite seldom (1-2%), but usually leads to death at 2-3-year age.

Fenilketonuriya of the third type – is characterized by deficit of tetrahydrobiopterine. Symptoms of a fenilketonuriya of this type include mental retardation owing to a nanocephalia – reduction of volume of a brain.

Fenilketonuriya reasons

Mutations of the gene which is on the 12th chromosome are considered as the main reasons for development of a fenilketonuriya in children. Related marriages increase risk of emergence of anomaly.

At deficit of certain enzymes increase in blood of derivatives of phenylalanine which have the poisoning effect on a nervous system of the child is observed. Fenilketonuriya is inherited approximately equally both by boys, and girls.

Fenilketonuriya symptoms

Symptoms of a fenilketonuriya are shown not at once. In most cases, it is almost impossible to suspect a fenilketonuriya at children right after the birth. By sight the child looks healthy, is born in time and with a normal weight. But in several weeks fenilketonuriya symptoms are shown. Severe vomiting is considered the main symptom of a disease. During the period from two to six months, both mother, and the treating doctor can notice lag of the child in mental and physical development.

The children sick with a fenilketonuriya, after other peers begin to sit and go. Also explicit symptom of a fenilketonuriya is the increased perspiration with a characteristic "mouse" smell of sweat. Spasms, irritability, slackness, a capriciousness and tearfulness, reduction of the size of the head, an enanthesis are observed. At the children sick with a fenilketonuriya, teeth are late cut through.

With development of a fenilketonuriya the muscle tone raises that is characterized by a certain pose at the child which is called still "the tailor's pose" (the hands bent in joints and legs).

Treatment of a fenilketonuriya

The only treatment of a fenilketonuriya is observance of a diet which needs to adhere more than ten years after diagnosis. The children sick with a fenilketonuriya cannot acquire a large amount of phenylalanine therefore there are certain norms of its consumption which depend on age. The child up to two months can consume no more than 60 mg/kg of mass of phenylalanine, and children are more senior than six years – no more than 10-15 mg/kg.

As for breastfeeding then it is necessary to follow the strict rules. Mother has to control amount of breast milk which is drunk by the child. Therefore for feeding it is necessary to use only the decanted milk and in quantity which is authorized for a certain age of the child. For this purpose there are special tables with norms of consumption of phenylalanine, and also a formula of calculation of amount of breast milk in day. Finish feeding the child special mixes which do not contain phenylalanine.

Introduction of a feeding up at children with a fenilketonuriya is begun with fruit and berry juice. As firm food offer the child vegetable purees without milk addition. Use protein-free grain and nonmilk porridges on the basis of rice or cornmeal.

Treatment of a fenilketonuriya by means of food includes refusal or very limited consumption of such products as fish, meat, bakery products, sausages, cottage cheese, eggs, chocolate, bean, nuts and grain. These products contain a large amount of protein. Fruit and vegetables enter into a diet taking into account calculation of amount of phenylalanine in them.

Medicinal treatment of a fenilketonuriya assumes reception of vitamins, drugs of calcium, iron and phosphorus. Administration of drugs for improvement of cerebral circulation, microcirculation and fabric exchange is also shown. Recommend occupations physiotherapy exercises and massage.