Essential and Conditionally Essential Amino Acid Profile in West Kazakhstan Children with Suspected Inborn Errors of Metabolism

Abstract

Measuring the concentration of amino acids in the blood and compiling a metabolic profile of amino acids, taking into account the influence of factors such as age, gender, body weight, region of residence, is extremely important in the diagnosis of amino acid metabolic disorders, especially when conducting selective screening for inborn errors of metabolism (IEM). Aims: To describe the metabolic profile of essential and conditionally essential amino acids in samples of dried blood spots from children in Western Kazakhstan with suspected IEM using LC-MS/MS technology (liquid chromatography-tandem mass spectrometry). Methods: The cross-sectional study included 200 clinical-risk children of West Kazakhstan aged one day to 18 years, 52.5 % male and 47.5 % female. Depending on their age, the children were divided into the following groups: group A (newborns, age 1-30 days), group B (age 1 month -7 years) and group C (age 8-18 years). Blood samples on Guthrie cards were collected and quantified by LC-MS/MS. Nonparametric statistical approaches were used. The concentrations of arginine, glycine, leucine, isoleucine, hydroxyproline, methionine, phenylalanine, proline, tyrosine, valine in dried blood spots of children with suspected IEM were determined. Results: Significant differences were established between children with suspected IEM of different age groups in the concentrations of hydroxyproline, arginine, glycine, isoleucine, leucine, phenylalanine, proline, tyrosine and valine. A negative correlation with age for the majority of essential and conditionally essential Amino Acids indicates their decline with age in children with suspected hereditary metabolic diseases. Significant differences between groups of female and male children with suspected IEM were established only in the concentration of methionine in dried blood spots. The highest values were determined in female group. Conclusion: The results of this study may be important in conducting selective screening for IEM in various age groups of the pediatric population.