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control diminishes
with age1,2

Compliance with blood phenylalanine (Phe) level recommendations declines with age1

Guidelines recommend lifetime maintenance of Phe concentrations ≤360 μmol/L. However, phenylalanine (Phe) control typically drops off during adolescence, increasing the severity of neuropsychological symptoms and negatively impacting life trajectory.2,3

67% of adults with phenylketonuria (PKU) are above American College of Medical Genetics and Genomics target Phe ranges image
Compliance with blood Phe levels bar graph image

Adapted from Jurecki et al. Mol Genet Metab. 2017.

Young adults and adults with PKU can become trapped in a cycle of decline4

  • Uncontrolled PKU inhibits daily functioning, contributing to poor management4,5
  • Patients with prolonged, elevated Phe levels often lack self-awareness of the severity of their symptoms4
  • At the same time, high blood Phe levels can lead to executive function impairments that make PKU management more challenging4
Cycle of decline with PKU image

Learn more about PKU

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Why metabolic control is
so important3,5,6

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management options

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  1. Jurecki ER, Cederbaum S, Kopesky J, et al. Adherence to clinic recommendations among patients with phenylketonuria in the United States. Mol Genet Metab. 2017;120(3):190-197.
  2. Brown CS, Lichter-Konecki U. Phenylketonuria (PKU): a problem solved? Mol Genet Metab Rep. 2016;6:8-12.
  3. Vockley J, Andersson HC, Antshel KM, et al; American College of Medical Genetics and Genomics Therapeutic Committee. Phenylalanine hydroxylase deficiency: diagnosis and management guidelines. Genet Med. 2014;16(2):188-200.
  4. Thomas J, Nguyen-Driver M, Bausell H, Breck J, Zambrano J, Birardi V. Strategies for successful long-term engagement of adults with phenylalanine hydroxylase deficiency returning to the clinic. J Inborn Errors Metab Screen. 2017;5:1-9.
  5. Bilder DA, Noel JK, Baker ER, et al. Systematic review and meta-analysis of neuropsychiatric symptoms and executive functioning in adults with phenylketonuria. Dev Neuropsychol. 2016;41(4):245-260.
  6. Ashe K, Kelso W, Farrand S, et al. Psychiatric and cognitive aspects of phenylketonuria: the limitations of diet and promise of new treatments. Front Psychiatry. 2019;10:561. doi:10.3389/fpsyt.2019.00561.
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