CATALASE C-262T GENE POLYMORPHISM AND CHANGES IN VENTILATION LUNG CAPACITY IN CHILDREN/RESIDENTS OF RADIOACTIVELY CONTAMINATED TERRITORIES

Objective: to determine the association of catalase С-262Т gene polymorphism with the presence of bronchial hyperreactivity in children living in radioactively contaminated territories. Materials and methods. There were examined school-age children-residents of radioactively contaminated territories (RCT), who did not have clinical signs of respiratory pathology. Catalase (CAT) С-262Т gene deletion polymorphism was studied in the molecular genetic laboratory of the State Institution «Reference Center for Molecular Diagnostic of Public Health Ministry of Ukraine». Determination of the polymorphic variant by the catalase С-262Т gene was performed by Polymerase Chain Reaction (PCR) using specific oligonucleotide primers, followed by Restriction Fragment Length Polymorphism (RFLP) analysis. The CAT С-262Т gene polymorphism in children living in RCT was compared with that in the reference group of practically healthy individuals. Ventilation lung capacity was performed by computer spirometry according to the analysis of the loop «the flow–volume». A pharmacological inhalation test with a bronchodilator that acts on β2-adrenergic receptors of the lungs was used to detect early changes in the ventilatory capacity of the lungs – bronchial hyperreactivity. Results. Comparative analysis showed that in the presence of bronchial hyperreactivity in children living in RCT, the CT genotype was more common than in children without bronchial hyperreactivity, and the frequency of the CC genotype was correspondingly reduced. There was a trend towards a decrease in the frequency of the TT genotype. An analysis of the frequency distribution of allelic variants of the CAT С-262Т gene polymorphism in children living in the RCT revealed a tendency to increase in the frequency of the T-allele and according to the decrease in the frequency of C-allele in the presence of bronchial hyperreactivity. Сonclusions. Thus, among children living in RCT, CT-homozygotes of CAT С-262Т gene polymorphism had bronchial hyperreactivity probably more often than CC-heterozygotes. In the presence of bronchial hyperreactivity, there was a trend towards an increase in the frequency of the T-allele and, accordingly, a decrease in the frequency of the Callele. Key words: children, radioactively contaminated areas, bronchial hyperreactivity, catalase С-262Т gene polymorphism.