Júlio-Costa Annelise, Martins Aline Aparecida Silva, Wood Guilherme, de Almeida Máira Pedroso, de Miranda Marlene, Haase Vitor Geraldi, Carvalho Maria Raquel Santos
Departamento de Psicologia, FAFICH, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
Programa de Pós-graduação em Neurociências, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
Front Psychol. 2019 May 15;10:1013. doi: 10.3389/fpsyg.2019.01013. eCollection 2019.
Math anxiety (MA) is a phobic reaction to math activities, potentially impairing math achievement. Higher frequency of MA in females is explainable by the interaction between genetic and environmental factors. The molecular-genetic basis of MA has not been investigated. The Val158Met polymorphism, which affects dopamine levels in the prefrontal cortex, has been associated with anxiety manifestations. The valine allele is associated with lower, and the methionine allele with higher, dopamine availability. In the present study, the effects of sex and Val158Met genotypes on MA were investigated: 389 school children aged 7-12 years were assessed for intelligence, numerical estimation, arithmetic achievement and MA and genotyped for Val158Met polymorphism. The Math Anxiety Questionnaire (MAQ) was used to assess the cognitive and affective components of MA. All genotype groups of boys and girls were comparable regarding genotype frequency, age, school grade, numerical estimation, and arithmetic abilities. We compared the results of all possible genetic models: codominance (Val/Val vs. Val/Met vs. Met/Met), heterosis (Val/Met vs. Val/Val Met/Met), valine dominance (Val/Val Val/Met vs. Met/Met), and methionine dominance (Met/Met Val/Met vs. Val/Val). Models were compared using AIC and AIC weights. No significant differences between girls and boys and no effects of the Val158Met polymorphism on numerical estimation and arithmetic achievement were observed. Sex by genotype effects were significant for intelligence and MA. Intelligence scores were higher in Met/Met girls than in girls with at least one valine allele (valine dominance model). The best fitting model for MA was heterosis. In Anxiety Toward Mathematics, heterozygous individuals presented MA levels close to the grand average regardless of sex. Homozygous boys were significantly less and homozygous girls significantly more math anxious. Heterosis has been seldom explored, but in recent years has emerged as the best genetic model for some phenotypes associated with the Val158Met polymorphism. This is the first study to investigate the genetic-molecular basis of MA.
数学焦虑（MA）是对数学活动的一种恐惧反应，可能会损害数学成绩。女性中MA的高频率可通过遗传和环境因素之间的相互作用来解释。MA的分子遗传学基础尚未得到研究。影响前额叶皮质多巴胺水平的Val158Met多态性与焦虑表现有关。缬氨酸等位基因与较低的多巴胺可用性相关，而甲硫氨酸等位基因与较高的多巴胺可用性相关。在本研究中，调查了性别和Val158Met基因型对MA的影响：对389名7至12岁的学童进行了智力、数字估计、算术成绩和MA评估，并对Val158Met多态性进行基因分型。使用数学焦虑问卷（MAQ）来评估MA的认知和情感成分。男孩和女孩的所有基因型组在基因型频率、年龄、年级、数字估计和算术能力方面具有可比性。我们比较了所有可能的遗传模型的结果：共显性（Val/Val与Val/Met与Met/Met）、杂种优势（Val/Met与Val/Val + Met/Met）、缬氨酸显性（Val/Val + Val/Met与Met/Met）和甲硫氨酸显性（Met/Met + Val/Met与Val/Val）。使用AIC和AIC权重比较模型。未观察到女孩和男孩之间的显著差异，也未观察到Val158Met多态性对数字估计和算术成绩的影响。性别与基因型的交互作用对智力和MA有显著影响。Met/Met女孩的智力得分高于至少有一个缬氨酸等位基因的女孩（缬氨酸显性模型）。MA的最佳拟合模型是杂种优势。在对数学的焦虑方面，杂合个体的MA水平接近总体平均值，无论性别如何。纯合子男孩的数学焦虑明显较少，纯合子女孩的数学焦虑明显较多。杂种优势很少被探讨，但近年来已成为与Val158Met多态性相关的一些表型的最佳遗传模型。这是第一项研究MA的遗传分子基础的研究。
