Assessment of the Genetic Characteristics of a Generation Born during a Long-Term Socioeconomic Crisis.

BACKGROUND: A socioeconomic crisis in Russia lasted from 1991 to 1998 and was accompanied by a sharp drop in the birth rate. The main factor that influenced the refusal to have children during this period is thought to be prolonged social stress. METHODS: comparing frequencies of common gene variants associated with stress-induced diseases among generations born before, after, and during this crisis may show which genes may be preferred under the pressure of natural selection during periods of increased social stress in urban populations. RESULTS: In the "crisis" group, a statistically significant difference from the other two groups was found in rs6557168 frequency (p = 0.001); rs4522666 was not in the Hardy-Weinberg equilibrium in this group, although its frequency did not show a significant difference from the other groups (p = 0.118). Frequencies of VNTRs in SLC6A3 and MAOA as well as common variants rs17689918 in CRHR1, rs1360780 in FKBP5, rs53576 in OXTR, rs12720071 and rs806377 in CNR1, rs4311 in ACE, rs1800497 in ANKK1, and rs7412 and rs429358 in APOE did not differ among the groups. CONCLUSIONS: a generation born during a period of prolonged destructive events may differ from the rest of the gene pool of the population in some variants associated with personality traits or stress-related disorders.

Prevalence of Common Alleles of Some Stress Resilience Genes among Adolescents Born in Different Periods Relative to the Socioeconomic Crisis of the 1990s in Russia.

Social stress is common among people and is considered one of the causes of the declining birth rate. Predisposition to stress and stress-induced disorders is largely determined genetically. We hypothesized that due to differences in stress resistance, carriers of different genetic variants of genes associated with stress resilience and stress-induced diseases may have dissimilar numbers of offspring under conditions of long-term social stress. To test this hypothesis, a comparative analysis of frequencies of seven common polymorphic regions [exon 3 variable number of tandem repeats (VNTR) of the DRD4 gene, rs4680 of COMT, STin2 VNTR and the 5-HTTLPR (rs774676466) insertion/deletion polymorphism of SLC6A4, rs4570625 of TPH2, rs6265 of BDNF, and rs258747 of NR3C1] was performed on standardized groups of randomly selected adolescents born before, during, and after severe socioeconomic deprivation (the crisis of the 1990s in Russia). There were significant differences in frequencies of "long" alleles of the DRD4 gene (p = 0.020, χ2 = 5.492) and rs4680 (p = 0.022, χ2 = 5.289) in the "crisis" group as compared to the combined "noncrisis" population. It is possible that the dopaminergic system had an impact on the successful adaptation of a person to social stress.

Helicobacter pylori seropositivity among adolescents in Novosibirsk, Russia: prevalence and associated factors.

OBJECTIVES: We have reported previously that infection is widespread among adults in Siberia, in whom prevalence rates range from 70% to 90%. The present study was undertaken to determine the seroprevalence of infection and its relation to social factors in a community-based population of adolescents in Novosibirsk, Western Siberia. METHODS: All students in forms 9 to 11 of four randomly selected secondary schools participated. A total of 423 students (180 boys, 243 girls; age, 14-17 years) completed structured questionnaire concerning their lifestyle, and sera were tested for using enzyme-linked immunosorbent assay (Pyloriset -New EIA-G; Orion Diagnostica, Finland). Personal information, including parental history, educational level, occupation, and smoking habits, were collected via a questionnaire. RESULTS: Overall, the seroprevalence of infection was 56.3%. Age, sex, smoking, alcohol consumption, number of children and pets in the household, and family history of gastric diseases were not associated with positivity. The predictors of infection were dwelling without running hot water supply and sewage (odds ratio [OR] = 2.4; 95% confidence interval [CI], 1.2-4.8), father's occupation as a manual worker (OR = 2.7; 95% CI, 1.5-5.0), mother's occupation as a manual worker (OR = 1.8; 95% CI, 1.0-3.0), father's lower educational attainment (OR = 2.1; 95% CI, 1.2-3.6), and father's smoking (OR = 1.8; 95% CI, 1.1-3.2). CONCLUSIONS: The prevalence of seropositivity among adolescents in Russia is higher than in developed countries. The infection is associated with lower socioeconomic status.