Well, disturbance (freezing) of this reaction, the observed
in violation of the synthesis of phenylalanine in the liver,
leads to severe hereditary disease - phenylketonuria.
Tyrosine is used by the body for the synthesis of thyroid hormones
cancer. A melanins, derivatives of tyrosine and phenylalanine,
provide pigmentation (color color) skin, eye
and hair.
Phenylketonuria , as it is called fenilalaninemiya,
fenilpirovinogradnaya mental retardation, a congenital
metabolic rate (metabolism), is characterized by increasing
levels of phenylalanine in the blood plasma and is accompanied by mental
retardation. The exact cause of mental retardation in
phenylketonuria is unknown, but it is a consequence
biochemical defect.
This hereditary disease is detected in the majority
people with a lower incidence occurs among Ashkenazi Jews
and African Americans. Frequency of phenylketonuria in the U.S. is
about 1 in 16,000 newborns. Clinical symptoms
phenylketonuria in newborns are not usually available, so
should be required to conduct laboratory screening (diagnosis).
In rare cases, there is lethargy and difficulty in
feeding. The majority of untreated patients, the disease
manifests a certain degree of mental retardation
(More pronounced), which is the main symptom
phenylketonuria.
Usually patients lighter skin, hair and eyes,
than their healthy relatives. Some children may
observed skin changes that resemble infant
eczema. For patients with phenylketonuria is characterized by profuse
neurological symptoms, especially changes are
reflexes. In older children, marked as
large and small epileptic fits, the deviations
EEG (electroencephalography) are found in 75 - 90% of cases.
being developed pronounced increase in activity, and psychosis,
often comes from patients with a nasty "rat" smell caused by the
presence of phenylacetic acid in urine and sweat. Diagnosis.
Once the newborn is getting milk (a source of
phenylalanine) for at least 48 hours, doctors perform
screening test for phenylketonuria. At the age of 4 -
6 weeks in the urine of a sick child can identify the product
the collapse of phenylalanine.
At this time hold another screening test for phenylketonuria.
The urinary test is performed after the newborn period,
and children from families where there is a patient with phenylketonuria,
it should be regularly repeated during the first year
life. Treatment consists of restricting the phenylalanine
with food in order to satisfy the need in this
essential amino acids, without exceeding it, to ensure a normal
growth and development, preventing the accumulation of phenylalanine in the body
and end-products of its metabolism. Requires continuous
observation of the level of phenylalanine in the blood of a child.
In the United States to replace the milk is widely used product lofenalak,
full in all respects, except for phenylalanine.
Allowed the use of low-protein natural foods
such as fasits, vegetables, some paints, etc. need
in phenylalanine is satisfied by the consumption of limited
number of natural protein and the residual amount of
phenylalanine lofenalake.
currently commercially available products, fully
purified from phenylalanine. The product contains phenyl-fries
all the ingredients except phenylalanine does not contain
fat, so their energy value is lower than other
products. Treatment by a physician should receive the first
days of life. Only early and consistent treatment to prevent
central nervous system and severe mental
retardation. If treatment is started after a 2 - 3 years of life,
it can be used only to limit a pronounced increase in
activity and to facilitate during seizures.