What Type of Mutation Occurs in PKU?
See below: Summary Disease characteristics. Phenyalanine hydroxylase (PAH) deficiency results in intolerance to the dietary intake of the essential amino acid phenylalanine and produces a spectrum of disorders including phenylketonuria (PKU), non-PKU hyperphenylalaninemia (non-PKU HPA), and variant PKU. Classic PKU is caused by a complete or near-complete deficiency of phenylalanine hydroxylase activity; without dietary restriction of phenylalanine, most children with PKU develop profound and irreversible mental retardation. Non-PKU HPA is associated with a much lower risk of impaired cognitive development in the absence of treatment. Variant PKU is intermediate between PKU and non-PKU HPA. Diagnosis/testing. PAH deficiency can be diagnosed by newborn screening in virtually 100% of cases based upon detection of the presence of hyperphenylalaninemia using the Guthrie microbial or other assays on a blood spot obtained from a heelprick. PKU is diagnosed in individuals with plasma phenylal
