Definition and causes
Fenylketonuri is a hereditary disease , Which is due to defect in the gene that provides for the formation of the enzymefenylalanin hydroksylase. This enzyme is found in liver, kidney and pancreas and destroys aminosyrenfenylalanin, Which is in general diet and breast milk. We become ill because the lack of degradation of fenylalanin resulting in an accumulation of toxic substances that particular cause damage to the brain and nervous system.
The disease belongs to the groupautosomalt recessivehereditary diseases. In these diseases inherits Monday a sick gene from each of his parents and therefore have two defective copies of the gene in its genome. If you inherit a sick gene from one parent and a recovery from the other parent, you are a carrier of the disease. Bearers will not be sick, but could give the disease gene on to their children (see also the article Genetics ).
Genes consists of DNA. Changes in the DNA of the gene is called a mutation and can cause the gene no longer operate normally and thus becomes sick. There are over 400 mutations in the gene for fenylalanin hydroksylase that can cause phenylketonuria.
Fenylketonuri is a rare disease in Denmark. The seen in some. 1 in 10,000 newborns.
Symptoms of phenylketonuria
The child is normal, just after birth. Gradually develop child mental retardation (in the old days called "feebleminded"). After the first year of life, most with untreated phenylketonuria an IQ of about. 50 (normally 100). Mental retardation covers delayed or incomplete development of thinking, language, motor skills (management of the body's movements) and social skills. Mental retardation is a difficult diagnosis to make in young children, including because it is difficult to test their various evn
The children often have a special appearance:
- Light skin.
- Blue eyes.
- Blondt hair.
Many of the children have a characteristic kroplugt of "musty cellar."
Many more untreated children develop psychiatric symptoms in the form of:
- Difficult to manage.
Often developed symptoms of the nervous system with:
- Increased muskelspænding (hypertension).
- Increased reflexes (hyperrefleksi).
Precautions and diagnosis
If we know that phenylketonuria occurs in the family, you can search genetic counselling . It could clarify whether it is necessary to be tested to see if you are a carrier of the disease.
If your child was healed by birth but soon thereafter is not progressing normally, one should consult a doctor. The diagnosis should be done already within the first leveuge, to avoid damage to the brain and nervous system. Therefore, in Denmark introduced a screening of all newborns for the disease. This is called PKU (phenylketonuria) and is a blood test. At the same time screener for Monday Toxoplasmosis and congenital hypotyreose . Diagnosis may also be provided on a urine, but this is the first secure several weeks after birth, where the damage has already occurred.
Consideration of phenylketonuria
The treatment is a specialistopgave and consists of a strict diet, which minimizes fenylalanin-consumed with the diet. It controls the diet with blood tests to ensure that the content of fenylalanin in the body does not get too high. For children in the first year of life, there are aminosyreblandinger with low levels of fenylalanin that can be used with infant formula.
Select and complications
If the diet is started on time and strictly adhered to, will the child developed quite normal. If the diagnosis is provided late, because the child has not been screened, there will be irreparable damage to the brain.
Prevention of phenylketonuria
As mentioned earlier offered to all newborn children in Denmark screening in 1. leveuge.