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Paediatric reference values for total homocysteine, tryptophan, tyrosine and phenylalanine in blood spots

Catharina E Bergwerff1, Marjolein Luman1, Henk J Blom2,3

  • 1a Clinical Neuropsychology section , Vrije Universiteit Amsterdam , Amsterdam , the Netherlands.

Scandinavian Journal of Clinical and Laboratory Investigation
|July 6, 2017
PubMed

Insights

This study establishes crucial pediatric reference values for blood spot amino acid concentrations, including total homocysteine, tryptophan, tyrosine, and phenylalanine. These findings provide essential clinical guidance for assessing children

Area of Science:

  • Clinical Chemistry
  • Paediatric Diagnostics
  • Biomarker Analysis

Background:

  • Accurate measurement of amino acid levels in children is vital for clinical practice.
  • Blood spot analysis offers a less invasive method for pediatric amino acid testing compared to venous blood sampling.
  • Current lack of established pediatric reference values for blood spot amino acids poses a diagnostic challenge.

Purpose of the Study:

  • To establish reference values for blood spot concentrations of total homocysteine, tryptophan, tyrosine, and phenylalanine in school-aged children.
  • To provide a foundational dataset for clinical interpretation of these amino acid levels in pediatric populations.

Main Methods:

  • Analysis of dried blood spots from 104 healthy school-aged children (6-12 years) using positive electrospray liquid chromatography-tandem mass spectrometry.
  • Inclusion of participants from diverse ethnic backgrounds and socioeconomic statuses, reflecting the general Dutch population.
  • Collection of demographic data from parents to ensure sample representativeness.

Main Results:

  • Established reference ranges for blood spot concentrations of total homocysteine, tryptophan, tyrosine, and phenylalanine in the studied pediatric cohort.
  • Demonstrated that blood spot amino acid concentrations were consistent between males and females.
  • Confirmed that blood spot amino acid concentrations were independent of age within the 6-12 year range.

Conclusions:

  • Successfully established the first paediatric reference values for blood spot concentrations of total homocysteine, tryptophan, tyrosine, and phenylalanine.
  • These newly established reference values are expected to significantly aid clinical practice in pediatric diagnostics.
  • The findings support the utility of blood spot analysis for routine amino acid monitoring in children.

Keywords:
Amino acidsclinical practiceschool-age childrenscreening

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