About Phenylktonuria (PKU)
Phenylketonuria (PKU) is an autosomal recessive inborn error of metabolism resulting from a deficiency of phenylalanine hydroxylase, an enzyme that catalyses the hydroxylation of phenylalanine to tyrosine, the rate-limiting step in phenylalanine catabolism. Loss of PAH activity results in increased concentrations of phenylalanine in the blood and toxic concentrations in the brain.
Major Signs and Symptoms
If a baby isn’t treated for PKU, they’ll start to develop the following symptoms:
- seizures.
- tremors, or trembling and shaking.
- stunted growth.
- hyperactivity.
- skin conditions, such as eczema.
- a musty odor of their breath, skin, or urine.
Incidence and Prevalence
PKU affects 600-1200 Australians. The condition is diagnosed at birth and it is listed on the New Born Screening tests.
Treatment
Nutrition therapy is the primary treatment for phenylalanine hydroxylase (PAH) deficiency that occurs in PKU, with the goals of lifelong nutrition therapy including normal physical growth and neurocognitive development, maintenance of adult health and normal gestational outcomes in pregnant women. Modified low protein foods should be introduced early to meet energy needs and maintain metabolic control, with individualised treatment plans necessary.
Importance of Compliance
Due to the complexity of treatment, adherence to dietary therapy diminishes with age, emphasising the need to provide a range of supplements to provide variety in treatment options for individuals with PKU of all ages. Importantly, improvements in behaviour and functioning have been documented in previously untreated individuals with PAH deficiency who have been placed on diet therapy, demonstrating the importance of a range of nutritional product options for individuals, including those who may go ‘off diet’ for a period and later return to dietary therapy.
Providing additional, palatable therapy options is likely to enhance adherence to therapy, supporting the need for new formulations of PKY nutritional supplements.
PKU easy Microtabs, PKU Easy Baby, PKU Easy Shake & Go, PKU Easy Liquid and PKU Go are available from orpharma and can be ordered by an approved pharmacist or via our Home Delivery Service. Please visit http://www.orpharma.com/products/medical-nutrition.
References
Blau, N., van Spronsen, F., et al. (2010). “Phenylketonuria.” Lancet 376: 1417-1427.
Camp, K., Parisi, M., et al. (2014). “Phenylketonuria scientific review conference: State of the science and future research needs.” Mol Genet Metab 112(2): 87-122.
Giovannini, M., Riva, E., et al. (2014). “Randomized controlled trial of a protein substitute with prolonged release on the protein status of children with phenylketonuria.” Journal of the American College of Nutrition 332: 103-110.
Singh, R., Rohr, F., et al. (2014). “Recommendations for the nutrition management of phenylalanine hydroxylase deficiency.” Genet Med 16(2): 121-131.
van Spronsen, F., van Rijn, M., et al. (2009). “Phenylalanine tolerance can already reliably be assessed at the age of 2 years in patients with pku.” J Inherit Metab Dis 32: 27–31.