What Is phenylketonuria (PKU disease)?
Phenylketonuria, also hyperphenylalaninaemia is an increased concentration of phenylalanine in the blood. The name is derived from the metabolite of phenylalanine, 3-phenylpyruvate (3-phenyl-2-oxopropanoic), which is excreted in the urine (ICD-10 E70.0).
Phenylketonuria (PKU) is a recessive hereditary metabolic disorder, which occurs in 1 in 18,000 children. Only if both parents are carriers of the PKU gene, they can get a child suffering from PKU. If neither of the two parents suffering from PKU itself but both be carriers, the likelihood of PKU for each child is 25%.
When PKU is the enzyme phenylalanine hydroxylase (PAH), which degrades the amino acid phenylalanine, absent or inoperative, so that this amino acid accumulates in the blood and the spinal fluid. This causes a chemical process in which nerve cells damaged. This eventually leads to brain damage. Patients with untreated PKU are generally mentally handicapped with additional behavioral problems, and many suffer from difficult to treat skin conditions such as eczema. The PAH gene is located on chromosome 12q.
Phenylketonuria (PKU disease) treatment
Phenylketonuria (PKU) can be treated with a lifelong diet that is low in protein. This means that very small protein, there can be taken per day. Untreated, the disease leads to severe mental retardation. For most foods, the label indicates the amount of protein. From this, the amount of phenylalanine can be calculated. In addition, the sweetener aspartame, a well-known (light products) source of phenylalanine which should be avoided.
Mental retardation occurs (where now known) or not. The effects of prolonged protein diet (still) not known. PKU patients do receive additional amino acid preparations and are lifelong controlled by a dietitian (e).
Since 1974, the heel prick test is performed in the Netherlands. All newborn babies have to be screened for their 5th day of life on this condition by means of this heel prick.