Predicting behavior problems in Korean preschoolers: interactions of the SLC6A4 gene and maternal negative affectivity
Junghee Ha 1, Hey Jung Jun 2, Hyewon Shin 3, Ick Joong Chung 4, Eunmie Park 5, Sung Kil Min 6, Eunjoo Kim 1*
1Department of Psychiatry and Institute of Behavioral Science in Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea, 2Department of Child and Family Studies, College of Human Ecology, Yonsei University, Seoul, Republic of Korea, 3Department of Child Studies, Seokeong University, Seoul, Republic of Korea, 4Department of Social Welfare, Ewha Womans University, Seoul, Republic of Korea, 5Department of Social Welfare, Seoul Jangsin University, Seoul, Republic of Korea, 6Department of Neuropsychiatry, Hyoja Hospital, Yonin, Republic of Korea
Received: December 29, 2017; Revised: March 22, 2018; Accepted: March 28, 2018; Published online: March 28, 2018.
© The Korean College of Neuropsychopharmacology. All rights reserved.

Objective: This study aimed to investigate whether maternal negative affectivity (MNA) moderates the effect of genetic polymorphism of SLC6A4 on behavior problems in children.
Methods: Study participants comprised 143 preschoolers and their mothers from South Korea. The Childhood Behavior Checklist (CBCL) and Emotionality, Activity, and Sociability (EAS) Adult Scale were used to measure child behavior and maternal affectivity. DNA from saliva was genotyped to determine serotonin transporter polymorphism.
Results: Maternal negative affectivity appeared to exert effects in externalizing (b=5.78, p<.001) and internalizing problems (b=6.09, p<.001). Interaction between SLCA4 polymorphism and MNA showed effects on externalizing (b = -7.62, p <.01) and internalizing problems. (b = -9.77, p<.01) Children with two short alleles showed considerable differences in both externalizing and internalizing problems according to MNA; however, children with one short allele or none showed relatively few differences in behavior problems due to maternal affectivity.
Conclusion: The effect of SLC6A4 polymorphism on child behavior seemed to be moderated by MNA. In addition, the impact of MNA was found to vary based on a child’s genetic risk. High MNA may trigger the risk allele while low MNA causes the risk allele to illicit less behavior problems. Children with two short variants of the SLC6A4 gene may benefit from intervention that modulates MNA.
Keywords: SLC6A4, maternal negative affectivity, internalizing, externalizing, preschoolers, poor emotional regulation, 5-HTTLPR