Predicting childhood effortful control from interactions between early parenting quality and children's dopamine transporter gene haplotypes

Abstract

Children's observed effortful control (EC) at 30, 42, and 54 months (n = 145) was predicted from the interaction between mothers' observed parenting with their 30-month-olds and three variants of the solute carrier family C6, member 3 (SLC6A3) dopamine transporter gene (single nucleotide polymorphisms in intron8 and intron13, and a 40 base pair variable number tandem repeat [VNTR] in the 3'-untranslated region [UTR]), as well as haplotypes of these variants. Significant moderating effects were found. Children without the intron8-A/intron13-G, intron8-A/3'-UTR VNTR-10, or intron13-G/3'-UTR VNTR-10 haplotypes (i.e., haplotypes associated with the reduced SLC6A3 gene expression and thus lower dopamine functioning) appeared to demonstrate altered levels of EC as a function of maternal parenting quality, whereas children with these haplotypes demonstrated a similar EC level regardless of the parenting quality. Children with these haplotypes demonstrated a trade-off, such that they showed higher EC, relative to their counterparts without these haplotypes, when exposed to less supportive maternal parenting. The findings revealed a diathesis-stress pattern and suggested that different SLC6A3 haplotypes, but not single variants, might represent different levels of young children's sensitivity/responsivity to early parenting.

Figure 1

Measurement model for the effortful control construct. Factor loadings were unstandardized. After fixing the residual variance, any correlated error variances between the indicators were no longer taken into account. ^a30-GB, 42-GB, 54-GB: gift bag task at 30, 42, and 54 months, respectively. ^b30-RT, 42-RT, 54-RT: rabbit/turtle task at 30, 42, and 54 months, respectively. ^c30-DT, 42-DT, 54-DT: dinky toys task at 30, 42, and 54 months, respectively.

Figure 2

SLC6A3 intron8-A/intron13-G haplotype and maternal parenting quality in predicting childhood effortful control. Simple slopes of maternal parenting quality were 8.64 and 1.44 for nAG and AG groups, respectively. The asterisks indicate a significant simple slope of maternal parenting quality. ***p < .001.

Figure 3

SLC6A3 intron8-A/3′UTR VNTR-10 haplotype and maternal parenting quality in predicting childhood effortful control. Simple slopes of maternal parenting quality were 9.28 and 1.39 for nA10 and A10 groups, respectively. The asterisks indicate a significant simple slope of maternal parenting quality. ***p < .001.

Figure 4

SLC6A3 intron13-G/3′UTR VNTR-10 haplotype and maternal parenting quality in predicting childhood effortful control. Simple slopes of maternal parenting quality were 9.22 and 2.13 for nG10 and G10 groups, respectively. The asterisks indicate a significant simple slope of maternal parenting quality. ***p < .001.