PKU. Food for thought

Promotie: mw. M. Hoeksma, 14.45 uur, Academiegebouw, Broerstraat 5, Groningen

Proefschrift: PKU. Food for thought

Promotor(s): prof.dr. P.J.J. Sauer

Faculteit: Medische Wetenschappen

Contact: via de persvoorlichters van het UMCG, tel. 050-361 2200, e-mail: voorlichting bvl.umcg.nl

PKU. Food for thought

Patients suffering from Phenylketonuria (PKU) cannot metabolize the amino acid phenylalanine. Therefore, the phenylalanine concentration in blood increases. Without treatment these patients become mentally retarded and they often develop epilepsy. PKU is treated with a strict diet low in portein, i.e. no meat, poultry or dairy products and a limited amount of grains, fruits and vegetables. This diet is supplemented with a synthetic mixture of amino acids, containing all amino acids but phenylalanine.

The research that was performed showed that the dietary treatment is not optimal yet. The growth of PKU patients could be enhanced by optimizing the current amino acid mixtures. Another finding was that there are no differences in the metabolism when a large and a small bolus of amino acids is consumed. This could mean that PKU patients can take their amino acid mixture in one bolus instead of three smaller ones. This could decreases the social problems PKU patients encounter.

The blood-brain barrier seems to play an important role in the cascade leading to brain damage in PKU patients. The phenylalanine concentration in blood is high, causing an increased transport of phenylalanine into the brain. The transport-system that transports amino acids from blood to brain is not capable of transporting the other amino acids into the brain. A shortage of other amino acids in the his should be investigated further in lead to mental retardation. The results of this research support this hypothesis. This should be investigated further before firm conclusions can be drawn.