eMedicine Specialties > Pediatrics: Genetics and Metabolic Disease > Metabolic Diseases

Hyperphenylalaninemia: Follow-up

Author: Georgianne L Arnold, MD, Director of Inherited Metabolic Disorders Clinic, Department of Pediatrics and Genetics, Associate Professor, University of Rochester School of Medicine and Dentistry
Contributor Information and Disclosures

Updated: Feb 13, 2009

Follow-up

Further Outpatient Care

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

Deterrence/Prevention

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

Prognosis

  • 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.

Miscellaneous

Medicolegal Pitfalls

  • Failure to provide adequate dietary phenylalanine, an essential amino acid
  • Failure to recommend adequate phenylalanine restriction
  • Failure to acknowledge the teratogenic effects of phenylalanine in pregnant women

Special Concerns

  • Excessively low phenylalanine levels can cause poor growth; all patients on dietary restrictions require careful follow-up.
  • Although elevated maternal phenylalanine levels are associated with birth defects, excessively low levels during pregnancy are also associated with poor fetal growth and microcephaly.
  • A few patients with mild-to-moderate elevations of phenylalanine later present with levels requiring dietary treatment. For this reason, follow-up over time is recommended.
 


More on Hyperphenylalaninemia

Overview: Hyperphenylalaninemia
Differential Diagnoses & Workup: Hyperphenylalaninemia
Treatment & Medication: Hyperphenylalaninemia
Follow-up: Hyperphenylalaninemia
Multimedia: Hyperphenylalaninemia
References

References

  1. 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. Oct 2007;30(5):700-7. [Medline].

  2. Matalon R, Michals-Matalon K, Koch R, et al. Response of patients with phenylketonuria in the US to tetrahydrobiopterin. Mol Genet Metab. Dec 2005;86 Suppl 1:S17-21. [Medline].

  3. 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. Dec 30 2008;105(52):20894-9. [Medline].

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

  5. 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.

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

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

  8. Gassio R, Artuch R, Vilaseca MA, et al. Cognitive functions in classic phenylketonuria and mild hyperphenylalaninemia: experience in a pediatric population. Dev Med Child Neurol. 2005;47:443-8. [Medline].

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

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

Further Reading

Keywords

hyperphenylalaninemia, phenylketonuria, benign PKU, mild PKU, nonphenylketonuric hyperphenylalaninemia,  phenylalanine, microcephaly, mental retardation, birth defects, maternal hyperphenylalaninemia, tetrahydrobiopterin deficiency, enzyme defect

Contributor Information and Disclosures

Author

Georgianne L Arnold, MD, Director of Inherited Metabolic Disorders Clinic, Department of Pediatrics and Genetics, Associate Professor, University of Rochester School of Medicine and Dentistry
Georgianne L Arnold, MD is a member of the following medical societies: American College of Medical Genetics, American Society of Human Genetics, Society for Inherited Metabolic Disorders, and Society for the Study of Inborn Errors of Metabolism
Disclosure: Biomarin Grant/research funds clinical trial

Medical Editor

Christian J Renner, MD, Consulting Staff, Department of Pediatrics, University Hospital for Children and Adolescents, Erlangen, Germany
Disclosure: Nothing to disclose.

Pharmacy Editor

Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine
Disclosure: Pfizer Inc Stock Investment from financial planner; Avanir Pharma Stock Investment from financial planner ; WebMD Salary and stock Employment and investment from financial planner

Managing Editor

Margaret McGovern, MD, PhD, Vice Chair, Professor, Department of Human Genetics, Mount Sinai School of Medicine
Margaret McGovern, MD, PhD is a member of the following medical societies: American Academy of Pediatrics and American Society of Human Genetics
Disclosure: Nothing to disclose.

CME Editor

Paul D Petry, DO, FACOP, FAAP, Consulting Staff, Freeman Pediatric Care, Freeman Health System
Paul D Petry, DO, FACOP, FAAP is a member of the following medical societies: American Academy of Osteopathy, American Academy of Pediatrics, American College of Osteopathic Pediatricians, and American Osteopathic Association
Disclosure: Nothing to disclose.

Chief Editor

Bruce Buehler, MD, Professor, Department of Pediatrics, Pathology and Microbiology, Executive Director, Hattie B Munroe Center for Human Genetics and Rehabilitation, 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 Mental Retardation, American College of Medical Genetics, American College of Physician Executives, American Medical Association, and Nebraska Medical Association
Disclosure: Nothing to disclose.

 
 
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