Objective:

Autism spectrum disorder (ASD) is heritable, and younger siblings of ASD probands are at higher likelihood of developing ASD themselves. Prospective MRI studies of siblings report that atypical brain development precedes ASD diagnosis, although the link between brain maturation and genetic factors is unclear. Given that familial recurrence of ASD is predicted by higher levels of ASD traits in the proband, the authors investigated associations between proband ASD traits and brain development among younger siblings.

Methods:

In a sample of 384 proband-sibling pairs (89 pairs concordant for ASD), the authors examined associations between proband ASD traits and sibling brain development at 6, 12, and 24 months in key MRI phenotypes: total cerebral volume, cortical surface area, extra-axial cerebrospinal fluid, occipital cortical surface area, and splenium white matter microstructure. Results from primary analyses led the authors to implement a data-driven approach using functional connectivity MRI at 6 months.

Results:

Greater levels of proband ASD traits were associated with larger total cerebral volume and surface area and larger surface area and reduced white matter integrity in components of the visual system in siblings who developed ASD. This aligned with weaker functional connectivity between several networks and the visual system among all siblings during infancy.

Conclusions:

The findings provide evidence that specific early brain MRI phenotypes of ASD reflect quantitative variation in familial ASD traits. Multimodal anatomical and functional convergence on cortical regions, fiber pathways, and functional networks involved in visual processing suggest that inherited liability has a role in shaping the prodromal development of visual circuitry in ASD.

中文翻译：

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婴儿视觉大脑发育和自闭症的遗传遗传责任

客观的：

自闭症谱系障碍 (ASD) 具有遗传性，自闭症谱系障碍先证者的弟弟妹妹本身患上自闭症谱系障碍的可能性更高。对兄弟姐妹的前瞻性 MRI 研究报告称，非典型大脑发育先于 ASD 诊断，尽管大脑成熟与遗传因素之间的联系尚不清楚。鉴于先证者 ASD 特征水平较高可以预测 ASD 家族复发，作者研究了先证者 ASD 特征与弟弟妹妹大脑发育之间的关联。

方法：

在 384 对先证者兄弟姐妹（89 对 ASD 一致）的样本中，作者检查了先证者 ASD 特征与兄弟姐妹在 6、12 和 24 个月时的关键 MRI 表型大脑发育之间的关联：大脑总体积、皮质表面积、轴外脑脊液、枕叶皮质表面积和压部白质微观结构。初步分析的结果促使作者在 6 个月时使用功能连接 MRI 实施数据驱动的方法。

结果：

先证者 ASD 特征水平越高，与患 ASD 的兄弟姐妹的大脑总体积和表面积越大，以及视觉系统组成部分的表面积越大和白质完整性降低相关。这与婴儿期所有兄弟姐妹之间的多个网络和视觉系统之间的功能连接较弱有关。

结论：

这些发现提供了证据表明，自闭症谱系障碍 (ASD) 的特定早期脑部 MRI 表型反映了家族性自闭症谱系障碍 (ASD) 特征的定量变异。视觉处理中涉及的皮质区域、纤维通路和功能网络的多模式解剖学和功能融合表明，遗传责任在塑造自闭症谱系障碍患者视觉回路的前驱发育中发挥着作用。