Background: Social orphans have a variety of behavioural and intellectual disorders. A number of specific polymorphisms in genes involved in the brain's dopamine and serotonin neurotransmitter systems have been implicated in the pathogenesis of various mental disorders. In this context, the study of candidate genes associated with the risk of emotional and behavioural disorders is by far the most relevant and promising in terms of a differentiated approach to subsequent psychoprophylaxis and treatment of mental pathology in children left without parental care. The aim of the study: To study the contribution of polymorphic variants of the TPH1, MAOA, HTR2A, DRD4, COMT, DBH, DRD2 genes to the development of mental disorders in children left without parental care. Materials and methods: A clinical examination of 516 social orphans was conducted in the period from 2018 to 2020, which also included molecular genetic typing of the following genes: rs1800532 TPH1(A218C), rs6323 MAOA (R297R), rs6313 HTR2A (T102C), rs1800955 DRD4 (C-521T), rs4680 COMT (G472A), rs1611115 DBH (C-1021T), rs1800497 DRD2 (Taq1A). The examination was conducted by analyzing DNA obtained from peripheral blood leukocytes. The frequencies of genotypes and alleles of these genes were determined. The distribution of genotype frequencies across the studied polymorphic loci was checked for compliance with the Hardy–Weinberg equilibrium using the Pearson chi-square criterion (χ2). The differences were considered significant at a significance level of p<0.05. Results: In the group of orphans with behavioral disorders, genotype AA and allele A of the polymorphic marker rs1800532 of the TPH1(A218C) gene were more common than in the control group (p=0.006). Genotype AA and allele A rs4680 of the COMT gene (G472A) and genotype T/T and allele T rs1800497 of the DRD2 gene (Taq1A) also showed significant differences between the study groups: they were more frequent in social orphans with conduct disorder (p=0.01 and p=0.003, respectively). Conclusion: The presence of polymorphisms of the rs1800532 TPH1(A218C), rs4680 COMT (G472A) and rs1800497 DRD2 (Taq1A) genes in social orphans is accompanied by an increased risk of mental disorders by 1.65 times or more
Background: Social orphans have a variety of behavioural and intellectual disorders. A number of specific polymorphisms in genes involved in the brain's dopamine and serotonin neurotransmitter systems have been implicated in the pathogenesis of various mental disorders. In this context, the study of candidate genes associated with the risk of emotional and behavioural disorders is by far the most relevant and promising in terms of a differentiated approach to subsequent psychoprophylaxis and treatment of mental pathology in children left without parental care. The aim of the study: To study the contribution of polymorphic variants of the TPH1, MAOA, HTR2A, DRD4, COMT, DBH, DRD2 genes to the development of mental disorders in children left without parental care. Materials and methods: A clinical examination of 516 social orphans was conducted in the period from 2018 to 2020, which also included molecular genetic typing of the following genes: rs1800532 TPH1(A218C), rs6323 MAOA (R297R), rs6313 HTR2A (T102C), rs1800955 DRD4 (C-521T), rs4680 COMT (G472A), rs1611115 DBH (C-1021T), rs1800497 DRD2 (Taq1A). The examination was conducted by analyzing DNA obtained from peripheral blood leukocytes. The frequencies of genotypes and alleles of these genes were determined. The distribution of genotype frequencies across the studied polymorphic loci was checked for compliance with the Hardy–Weinberg equilibrium using the Pearson chi-square criterion (χ2). The differences were considered significant at a significance level of p<0.05. Results: In the group of orphans with behavioral disorders, genotype AA and allele A of the polymorphic marker rs1800532 of the TPH1(A218C) gene were more common than in the control group (p=0.006). Genotype AA and allele A rs4680 of the COMT gene (G472A) and genotype T/T and allele T rs1800497 of the DRD2 gene (Taq1A) also showed significant differences between the study groups: they were more frequent in social orphans with conduct disorder (p=0.01 and p=0.003, respectively). Conclusion: The presence of polymorphisms of the rs1800532 TPH1(A218C), rs4680 COMT (G472A) and rs1800497 DRD2 (Taq1A) genes in social orphans is accompanied by an increased risk of mental disorders by 1.65 times or more