Correlation Study Between 5-HTTLPR,DRD4 Gene Polymorphism And Temperament In School-age Children

As one of relatively steady and lasting psychological characteristics,temperament determined by biological factors is a basis of personality development of human being.To explore the influence of polymorphism of 5-HTTLPR and DRD4,environment factors and their interaction on temperament,326 children aged 8?12 were recruited from schools in Hohhot in Inner Mongolia.Middle Childhood Temperament Questionnaire(MCTQ)was adopted to test the temperament dimensions of those children.Family condition questionnaire,Family Adaptability and Cohesion Scale(FACES?-CV)and Egma Minnen av Bardndosnauppforstran(EMBU)were applied to investigate their family environment.The 5-HTTLPR and DRD4 gene were divided into different types via Polymerase Chain Reaction.General Liner Model was used to examine the effects of environment and environment-environment interaction on children's temperament.The influence of the interaction of gene-gene and gene-environment on the temperament dimensions was analyzed by the Binary Logistic Regression.The results showed as follows:(1)In terms of environment factors,school-age children temperament was mainly connected with mother's reproductive age,father's overprotection and mother's rejection and denial.Besides gender,age,family cohesion and adaptability,parental educational background,parental rearing patterns and other factors,children's temperament dimensions were still related with certain interactions.(2)Polymorphism of 5-HTTLPR had an obvious influence on the temperament types(P<0.05).The child with "S" allele had a higher proportion of negative temperament.Polymorphism of 5-HTTLPR was significantly related to children's adaptability,response intensity and mood(P<0.05).The main influencing factors on the adaptability were mother's rejection and the interaction of father's punishment with 5-HTTLPR.The children with mother's rejection showed slow adaptability.The children with "S" allele and father's punishment were tend to be associated with slow adaptability.The main influencing factors on the reaction intensity were 5-HTTLPR and mother's rejection.The children with "S" allele and mother's rejection were tend to be associated with low reaction intensity.The main influencing factors on the mood were 5-HTTLPR and father's punishment interacted with 5-HTTLPR.The mood was negative in children with "S" allele.The children with "S"allele and father's punishment were tend to be associated with negative mood.(3)Polymorphism of DRD4 didn't obviously affect the temperament(P>0.05).DRD4 polymorphism had a remarkable correlation with activity level,reaction intensity,mood and persistency(P<0.05).The main influencing factors on the activity level were gender,mother's rejection and gender interacted with DRD4.Boys showed higher activity level than girls.The children with mother's rejection showed lower activity level.The girl with L-DRD4 showed lower activity level than the girl with S-DRD4.The main influencing factors on the reaction intensity were mother's rejection and its interaction with DRD4.The children with mother's rejection showed strong reaction intensity.The children with S-DRD4 and mother's rejection were tend to be associated with strong reaction intensity.The main influencing factors on the mood were father's punishment and family cohesion.The children with father's punishment or with low family cohesion showed negative mood.The main influencing factors on the persistency were mother's rejection and DRD4.The children with mother's rejection or with S-DRD4 were tend to be associated with low persistency.(4)5-HTTLPR and DRD4 polymorphisms interacted with each other influenced child reaction intensity and mood obviously.The children with 5-HTTLPR "L" allele and L-DRD4 were tend to be associated with low reaction intensity and negative mood.This study analyzed the environment factors that affected the temperament of school-age children and the correlation between temperament and the polymorphisms of 5-HTTLPR and DRD4.In addition,it explored the effects of the interaction of gene-environment and gene-gene on temperament.The results will provide some basic data for molecular biology concerning of temperament on school-age children and help parents and educators to adjust rearing styles according to children's temperament.