Phenylketonuria (PKU)

About Phenylketonuria

Phenylketonuria (PKU) is a genetic disorder caused by a deficiency of the enzyme phenylalanine hydroxylase, which is needed to convert the amino acid phenylalanine to tyrosine. When this enzyme is not working, phenylalanine builds up in the body, causing potentially fatal health problems, especially affecting the child's nervous system.

Causes: PKU is an autosomal recessive genetic disorder, meaning that a child may receive two copies of the mutated gene (one from each parent) to develop the disease. A sudden mutation in the PAH (phenylalanine hydroxylase) gene results in a deficiency of this enzyme.

Incidence: The incidence of phenylketonuria (PKU) in newborns ranges from about 1 in 10,000 to 1 in 20,000.

Semi-automatic solution

• Product name: Neonatal Phenylalanine
• Product code: NP-1000 / NP-4000
• Manufacturer: Wallac Oy – Finland
• Packing: 960 / 4800 tests
• Test principle:

The Neonatal Phenylalanine kit uses the fluorescent ninhydrin reaction method. This method is based on the dipeptide (L-leucyl-L-alanine) which enhances the luminescence of the phenylalanine-ninhydrin reaction product. Succinate buffer is used to optimize the luminescence and increase the specific intensity. Copper reagent (Copper reagent) is used to enhance the reaction and reduce the background. This method quantifies phenylalanine in the presence of other amino acids. The fluorescence signal is measured with an excitation wavelength of 390 nm and an emission wavelength of 486 nm.

Application: kit for screening Phenylketonuria in pus from 2-4 days old newborns on VICTORTM 2D fluorescence measuring device. Suitable for hospitals with small and medium sample volume.

Other equipment to test:

• VICTORTM 2D Fluorometer
• Wallac DBS Puncher or Panthera-Puncher™ 9 Dry Blood Puncher
• TriNEST™3 Microplate Incubator Shaker

Automated Solution

• Product Name: GSP® Neonatal Phenylalanine Kit
• Product Code: 3308-0010 / 3308-001B
• Manufacturer: Wallac Oy – Finland
• Packing: 1152 / 5760 Tests
• Test Principle:

GSP Neonatal Phenylalanine is an automated enzyme test, using the fluorescent phenylalanine dehydrogenase method. In the first reaction, the enzyme phenylalanine dehydrogenase converts phenylalanine to phenylpyruvate, generating a quantity of NADH. In the presence of NADH, the toxic drug resazurin is reduced to fluorescent resorufin in a reaction catalyzed by the enzyme diaphorase. The fluorescence signal of resofurin is measured using an appropriate light size at 505 nm and an emission light at 580 nm. This method measures the amount of phenylalanine present in the sample.

Application: Kit for screening phenylketonuria in dried pus from 2-4 day old newborns on the GSP® system. Suitable for hospital and center studies with medium and large sample volumes.

Other equipment to test:

• GSP® system
• Wallac DBS Puncher or Panthera-Puncher™ 9