Phenylketonuria (PKU) is an autosomal recessive inherited disorder. It is monogenetic and the connected gene (PAH) is located at the chromosome 12, which encodes for the hepatic enzyme [hydroxylase (PAH)]. People who suffer from this disorder have a strongly decreased activity of this enzyme and therefore suffer from the toxic effects of the accumulated [(Phe)] which leads mostly to mental retardation but also to certain other symptoms. Due to the ongoing development for treatment the patient can avoid most effects of the disease.
Phenylketonuria is a widely distributed an known disease, with rarely severe effects (with the right treatment). It affects the digestion of Phenylalanin(Phe) mostly through decreasing the efficiency of the Enzyme Phenylalaninhydroxilase (PAH). The main danger with this disease is the accumulation of Phe in the blood, which is toxic in high doses. Those will lead to mental retardation and other symptoms
N. Blau, J. Hennermann, U. Langenbeck, U. Lichter-Konecki, Diagnosis, classification, and genetics of phenylketonuria and tetrahydrobiopterin (BH4) deficiencies; Molecular Genetics and Metabolism 104 (2011) S2-S9