Abstract
OBJECTIVE: To investigate the association between anxiety-depression and 5-HTTLPR gene polymorphism in school-aged twins. METHODS: A 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. RESULTS: The 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). CONCLUSIONS: 5-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.