Medscape is available in 5 Language Editions – Choose your Edition here.


Hyperphenylalaninemia Follow-up

  • Author: Georgianne L Arnold, MD; Chief Editor: Bruce Buehler, MD  more...
Updated: Nov 30, 2015

Further Outpatient Care

Phenylalanine levels determine the need for further outpatient care in patients with hyperphenylalaninemia.



In general, patients should avoid consuming aspartame because phenylalanine is a primary component of aspartame.



Prognosis is excellent for normal development when treated as indicated.


Patient Education

Teach patients and parents about proper diet. Children should participate in their dietary planning as soon as they have that ability.

Contributor Information and Disclosures

Georgianne L Arnold, MD Faculty, Department of Pediatrics, Divison of Genetics, University of Pittsburgh School of Medicine

Georgianne L Arnold, MD is a member of the following medical societies: American College of Medical Genetics and Genomics, Society for Inherited Metabolic Disorders, Society for the Study of Inborn Errors of Metabolism, American Society of Human Genetics

Disclosure: Received grant/research funds from Biomarin for clinical trial.

Specialty Editor Board

Mary L Windle, PharmD Adjunct Associate Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Nothing to disclose.

Margaret M McGovern, MD, PhD Professor and Chair of Pediatrics, Stony Brook University School of Medicine

Margaret M McGovern, MD, PhD is a member of the following medical societies: American Academy of Pediatrics, American Society of Human Genetics

Disclosure: Nothing to disclose.

Chief Editor

Bruce Buehler, MD Professor, Department of Pediatrics and Genetics, Director RSA, University of Nebraska Medical Center

Bruce Buehler, MD is a member of the following medical societies: American Academy for Cerebral Palsy and Developmental Medicine, American Academy of Pediatrics, American Association on Intellectual and Developmental Disabilities, American College of Medical Genetics and Genomics, American Association for Physician Leadership, American Medical Association, Nebraska Medical Association

Disclosure: Nothing to disclose.

Additional Contributors

Christian J Renner, MD Consulting Staff, Department of Pediatrics, University Hospital for Children and Adolescents, Erlangen, Germany

Disclosure: Nothing to disclose.

  1. Prick BW, Hop WC, Duvekot JJ. Maternal phenylketonuria and hyperphenylalaninemia in pregnancy: pregnancy complications and neonatal sequelae in untreated and treated pregnancies. Am J Clin Nutr. 2012 Feb. 95(2):374-82. [Medline].

  2. Mak CM, Ko CH, Lam CW, et al. Phenylketonuria in Hong Kong Chinese: a call for hyperphenylalaninemia newborn screening in the Special Administrative Region, China. Chin Med J (Engl). 2011 Aug. 124(16):2556-8. [Medline].

  3. Crujeiras V, Aldámiz-Echevarría L, Dalmau J, Vitoria I, Andrade F, Roca I, et al. Vitamin and mineral status in patients with hyperphenylalaninemia. Mol Genet Metab. 2015 Aug. 115 (4):145-50. [Medline].

  4. Ten Hoedt AE, Hollak CE, Boelen CC, et al. "MY PKU": increasing self-management in patients with phenylketonuria. A randomized controlled trial. Orphanet J Rare Dis. 2011 Jun 27. 6:48. [Medline]. [Full Text].

  5. Burton BK, Grange DK, Milanowski A, et al. The response of patients with phenylketonuria and elevated serum phenylalanine to treatment with oral sapropterin dihydrochloride (6R-tetrahydrobiopterin): a phase II, multicentre, open-label, screening study. J Inherit Metab Dis. 2007 Oct. 30(5):700-7. [Medline].

  6. Matalon R, Michals-Matalon K, Koch R, Grady J, Tyring S, Stevens RC. Response of patients with phenylketonuria in the US to tetrahydrobiopterin. Mol Genet Metab. 2005 Dec. 86 Suppl 1:S17-21. [Medline].

  7. Sarkissian CN, Gamez A, Wang L, et al. Preclinical evaluation of multiple species of PEGylated recombinant phenylalanine ammonia lyase for the treatment of phenylketonuria. Proc Natl Acad Sci U S A. 2008 Dec 30. 105(52):20894-9. [Medline]. [Full Text].

  8. Agostoni C, Verduci E, Massetto N, et al. Long term effects of long chain polyunsaturated fats in hyperphenylalaninemic children. Arch Dis Child. 2003 Jul. 88(7):582-3. [Medline]. [Full Text].

  9. Berlin CM, Levy HL, Hanley WB. Delayed increase in blood phenylalanine concentration in phenylketonuric children initially classified as mild hyperphenylalaninemia. Screening. 1995. 4:35-39.

  10. Diamond A, Prevor MB, Callender G, Druin DP. Prefrontal cortex cognitive deficits in children treated early and continuously for PKU. Monogr Soc Res Child Dev. 1997. 62(4):i-v, 1-208. [Medline].

  11. Fisch RO, Matalon R, Weisberg S, Michals K. Phenylketonuria: current dietary treatment practices in the United States and Canada. J Am Coll Nutr. 1997 Apr. 16(2):147-51. [Medline].

  12. Gassio R, Artuch R, Vilaseca MA, et al. Cognitive functions in classic phenylketonuria and mild hyperphenylalaninaemia: experience in a paediatric population. Dev Med Child Neurol. 2005 Jul. 47(7):443-8. [Medline].

  13. Recommendations on the dietary management of phenylketonuria. Report of Medical Research Council Working Party on Phenylketonuria. Arch Dis Child. 1993 Mar. 68(3):426-7. [Medline]. [Full Text].

  14. Scriver CR, Kaufman S, Eijsensmith RC. The hyperphenylalaninemias. The Metabolic and Molecular Bases of Inherited Disease. 1995. Vol 1: 1015-76.

  15. Procházková D, Jarkovský J, Haňková Z, Konečná P, Benáková H, Vinohradská H, et al. Long-term treatment for hyperphenylalaninemia and phenylketonuria: a risk for nutritional vitamin B12 deficiency?. J Pediatr Endocrinol Metab. 2015 Nov 1. 28 (11-12):1327-32. [Medline].

Phenylalanine hydroxylase converts phenylalanine to tyrosine.
All material on this website is protected by copyright, Copyright © 1994-2016 by WebMD LLC. This website also contains material copyrighted by 3rd parties.