Object of the study: hereditary metabolic disturbances of amino acids (HMD AA). Purpose of the study: determination of the diagnostic significance of the quantitative analysis of free AA of the blood in combination with an assessment of the phenotype for revealing HMD in children. Methods of the study: biochemical analysis of AA with use of high-efficacy liquid chromatography (HELC), clinical-genealogical (somatogenetic study of the family); statistical methods. Practical significance: the quantitative analysis of free AA of the blood with use of HELC was introduced into the medical-genetic consulting practice. The account of the results of the study of AA levels together with the results of the assessment of the child’s phenotype enable us to improve the efficacy of diagnosing metabolic diseases (MD), to increase the number of verified nosological units. The use of the levels of free AA of the blood, calculated on the subsoil of the quantitative analysis of AA in children in the Kharkiv Region population, made it possible to increase the degree of informativeness of the obtained data. The use of the clinical-biochemical approach to the examination of children from the group of a high risk genetic risk gives a possibility to conduct an adequate genetic consulting on the basis of laboratory-confirmed diagnosis. The analysis of the phenotype, the state of different organs and systems in combination with the quantitative analysis of AA in a medical-genetic consulting makes it possible to approach a specifying diagnosis of other intermediate metabolic disturbances, rather than to diagnose HMD AA only. The revealing of the individual content of free AA provides a possibility to perform pathogenetic therapy and control over the treatment. Novelty of the obtained results: levels of free AA of the blood in healthy children and those with the signs of MD in the Kharkiv Region population were determined and quantitatively characterized. Conditions for analysing free AA of the blood were established, including the preparation of samples for the examination, chromatographic distribution and analysis of the obtained results. Phenotypical peculiarities in combination with the content of free AA of the blood in children with clinical signs of MD were studied. A spectrum of HMD AA in the children, whose families sought to medical-genetic help at the Kharkiv Specialized Medical-Genetic Centre (KSMGC), was revealed. A possibility of an early diagnosis of HMD AA was shown, provided the clinical-biochemical approach is used. A system of the clinical-biochemical approach in the diagnosis of HMD AA was worked out and introduced, thereby making it possible to increase the number of verified nosological units. On the subsoil of a complex assessment of the clinical and biochemical indices, phenotypical peculiarities were revealed in children with a higher level of some AA of their blood: glutaminic acid, glycine, alanine, proline. Pecuiarities in the phenotype of children with HMD AA were determined. Introduction: the results of the research are used in the work of KSMGC, Kriviy Rig Centre of Medical Genetics and Prenatal Diagnosis, the Department of Childhood Psychoneurology and Clinical Neurogenetics of the Institute of Neurology, Psychiatry and Narcology of the Academy of Medical Sciences of Ukraine, the Departments of Paediatrics and Clinical Genetics, Medical Biology, Genetics and Histology of Bukovina State Medical University, State Enterprise “Research Institute of Medical-Ecological Problems” of the Ministry of Health of Ukraine, as it is confirmed by the corresponding acts on introduction. Sphere of application: medicine, genetics.
