OBJECTIVETo study the effects of rs4274224 polymorphisms in the DRD2 gene, family factors and their interaction on the regularity in school-age children.

METHODSThe rs4274224 polymorphisms were genotyped using Sequenom Mass Array. The regularity was assessed based on the Middle Childhood Temperament Questionnaire (MCTQ). The parental rearing pattern was assessed with Egna Minnen av Bardnodnauppforstran (EMBU). The family function was assessed using Family Cohesion and Adaptability Scale (FACES II-CV).

RESULTSThe regularity score in children with AA genotype of rs4274224 in the DRD2 gene was significantly lower than in those with GA/GG genotype (2.9±0.6 vs 3.1±0.7; P<0.05). The results of multiple regression analysis showed that the regularity was related to child gender, father's education level and family adaptability. The results of logistic regression analysis showed that the main factors influencing the regularity were family adaptability and its interaction with rs4274224 polymorphisms. The regularity was better in children with high family adaptability than in those with low family adaptability (OR=0.112, P<0.01). The children with AA genotype and low family adaptability were tend to be associated with low regularity (OR=21.554, P<0.01).

CONCLUSIONSThe regularity based the temperament for school-age children might be influenced by family adaptability and its interaction with rs4274224 polymorphisms.

Child ; Female ; Genotype ; Humans ; Male ; Polymorphism, Genetic ; Receptors, Dopamine D2 ; genetics ; Surveys and Questionnaires ; Temperament

OBJECTIVETo investigate the association between dopamine D4 receptor gene DRD4 exon III 48bp variable number of tandem repeat (VNTR) polymorphism and temperament in school-aged children.

METHODSRandomized cluster sampling was used to select 350 healthy children aged 8-12 years, and a questionnaire survey was performed. Oral epithelial samples were collected from half of these children. The complete questionnaire data of 164 children with a high level of DNA in oral epithelial samples were included in this study. PCR was used for the typing of DRD4 exon III 48bp VNTR, and the effect of this gene and its interaction with the environment on temperament was analyzed.

RESULTSCompared with the children with S-DRD4 genotype, the children with L-DRD4 genotype had significantly lower scores on the four dimensions of activity level, reaction intensity, emotion essence, and persistence (P<0.05). The main effects of mother's rejection/denial (OR=2.281, P<0.05) and sex (OR=2.766, P<0.05) and the interaction between sex and DRD4 exon III 48bp VNTR (OR=0.582, P<0.05) had an influence on activity level. The main effect of DRD4 exon III 48bp VNTR (OR=0.314, P<0.01) and the interaction between this gene and mother's rejection/denial (OR=1.872, P<0.01) had an influence on reaction intensity. The main effect of DRD4 exon III 48bp VNTR (OR=0.420, P<0.05) and mother's rejection/denial (OR=2.236, P<0.05) had an influence on persistence.

CONCLUSIONSDRD4 exon III 48bp VNTR and its interaction with other factors may affect the activity level and reaction intensity of school-aged children.

OBJECTIVETo investigate the association between anxiety-depression and 5-HTTLPR gene polymorphism in school-aged twins.

METHODSA total of 147 pairs of twins (47 pairs of monozygotic twins, 100 pairs of dizygotic twins) aged 8-12 years from Baotou and Hohhot were selected as respondents. The Achenbach Child Behavior Checklist (CBCL) was used to calculate the scores of anxiety-depression factors in school-aged twins. The DNA was extracted from oral epithelial cells, and polymerase chain reaction was applied for 5-HTTLPR genotyping. The generalized estimating equation (GEE) was used to analyze the effect of 5-HTTLPR polymorphism and family environment on anxiety-depression in school-aged twins.

RESULTSThe children with LS and SS genotypes had significantly higher scores of anxiety-depression factors than those with LL genotype (χ2=3.938, P<0.05). The interaction of 5-HTTLPR genotype with family cohesion and family rearing patterns had a significant impact on the scores of anxiety-depression factors in twins (χ2=6.129 and 7.665, both P<0.05).

CONCLUSIONS5-HTTLPR genotype is significantly correlated with the scores of anxiety-depression factors in school-aged twins. In the family with high cohesion and an autocratic family rearing pattern, S allele may increase the possibility of anxiety-depression in twin children.

Anxiety ; genetics ; Child ; Depression ; genetics ; Female ; Genotype ; Humans ; Male ; Polymorphism, Genetic ; Serotonin Plasma Membrane Transport Proteins ; genetics ; Twins ; genetics

Objective To investigate the interaction between rs1800955 polymorphism of dopamine D4 receptor(DRD4) gene and negative life events on personality characteristics of Mongolian adolescents.Methods A total of 239 Mongolian adolescents aged 12-15 were assessed with Eysenck Personality Questionnaire(EPQ) and Adolescent Self-Rating Life Events Check List(ASLEC).The polymorphism of DRD4 gene rs1800955 was determined by improved multiple ligase detection reaction(iMLDR) technique.Results (1) The rs1800955 polymorphism of DRD4 gene was significantly correlated with psychoticism score of EPQ.The psychoticism score of individuals with CC genotype (4.94 ± 3.19) was higher than that of TT genotype (3.38±2.29),and the difference was statistically significant (P＜0.05).(2) The scores of psychoticism and neuroticism in Mongolian adolescents were positively correlated with the factors of negative life events(r=0.154-0.375,P＜0.05 or 0.01).(3) The interaction between the rs1800955 polymorphism of DRD4 gene and negative life events significantly affected the scores of psychoticism in Mongolian adolescents (C C genotype x interpersonal factor:B =-2.689,95 ％ CI =-4.589--0.789,x2 =7.695,P＜ 0.01).In individuals with CC genotype,the scores of psychoticism in those with high scores of interpersonal relatioriship factors were significantly higher than those with low scores of interpersonal relationship factors ((3.01 ± 0.71) vs (2.61 ±0.67);t =-3.066,P＜ 0.01).Conclusion The polymorphism of DRD4 gene rs 1800955 and its association with interpersonal factors play an important role in the psychoticism of Mongolian adolescents.The CC genotype is a risk factor of psychoticism,and the poor interpersonal relationship may increase the risk of individuals with CC genotype.