Phenylketonuria (PKU) is an inborn error of metabolism caused by the failure of the enzyme phenylalanine hydroxylase to metabolise phenylalanine, one of the amino acids. There is consequently an accumulation of phenylalanine in the body and consequent detrimental effects, particularly on mental development and physical growth.
In four parts:
1) Presentation: symptoms resulting from accumulation of phenylalanine in the blood shortly after birth;
2) Diagnostic Testing: the Guthrie test as well as more recent analyses; 3) Treatment: nature and necessity of a controlled diet;
4) Biochemistry: consequences of phenylalanine blockage in the normal biochemical pathway.