Phenylketonuria

Phenylketonuria (PKU) is an autosomal recessive inherited disease of metabolism phenylalanine is caused by pathogenic variants in the gene encoding phenylalanine hydroxylase (PAH), a deficiency of which leads to the accumulation of phenylalanine in the blood and brain. In the Czech Republic (CZ), this disease has been part of laboratory newborn screening (LNS) since 1975, performed on all babies born in the Czech Republic. Early detection makes it possible to initiate early treatment, primarily of adherence to a strict lifelong low-protein diet with phenylalanine restriction and administration of special mixtures of phenylalanine-free amino acids. With good compensation for the disease, the child's normal development is enabled. Due to more frequent migration, we can also encounter children who have not been examined for PKU within the LNS. Therefore, it should always be in physicians' awareness, especially in the differential diagnosis of psychomotor retardation, microcephaly and convulsions.