Certain behavioral characteristics of autism spectrum disorder can be found in otherwise healthy people. Individuals with difficulties in social adaptation may have subclinical autistic traits; however, effective biomarkers of these traits have not yet been established. There is a dire need for objective indices of these traits that combine behavior, brain images, and genetic information. In this study, we examined the association among a single nucleotide polymorphism of NRXN1 (rs858932; C/G), autistic traits, and brain structure in 311 healthy adults. We found that carriers of minor alleles (carriers of the G-allele) had significantly higher systemizing scores than major-allele (C-allele) homozygotes. Furthermore, the regional white matter volume in the right anterior limb of the internal capsule was significantly greater in carriers of the G-allele than in C-allele homozygotes. To the best of our knowledge, this is the first report of NRXN1 rs858932 being involved in systemizing and the brain structure of healthy adults. Our findings provide insight into the effects of genetics on autistic traits and their respective neural substrates.

自闭症谱系障碍的某些行为特征可以在其他健康人身上找到。社会适应困难的个体可能具有亚临床自闭症特征；然而，这些特征的有效生物标志物尚未建立。迫切需要结合行为、大脑图像和遗传信息的这些特征的客观指标。在这项研究中，我们检查了 311 名健康成年人的 NRXN1 (rs858932; C/G) 单核苷酸多态性、自闭症特征和大脑结构之间的关联。我们发现次要等位基因携带者（G 等位基因携带者）的系统化评分显着高于主要等位基因（C 等位基因）纯合子。此外，G等位基因携带者内囊右前肢的区域白质体积显着大于C等位基因纯合子。据我们所知，这是 NRXN1 rs858932 参与系统化和健康成人大脑结构的第一份报告。我们的研究结果提供了对遗传学对自闭症特征及其各自神经基质的影响的深入了解。