Impact of medical genetics concerning phenylketonuria: accomplishments, status and practical future possibilities.

Millions of newborn infants are screened for phenylketonuria (PKU) to prevent the inherited metabolic error by dietary treatment. For some PKU patients a relaxed low-phenylalanine diet will be lifelong. PKU-women must return to a strict low-phenylalanine diet before conception and during pregnancy to insure the delivery of a normal child. Two mutations that account for 60% of the PKU genes in Denmark are established and oligonucleotide probing enables carrier detection and genetic counselling. Primary hepatocytes can be successfully cultured and transformed with phenylalanine hydroxylase cDNA and somatic gene therapy of PKU may be a future possibility.