Children's Mental Health Research Center, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China.
Guangdong Mental Health Center, Guangdong General Hospital & Guangdong Academy of Medical Sciences, Guangzhou, China.
Autism Res. 2022 Apr;15(4):628-640. doi: 10.1002/aur.2686. Epub 2022 Feb 24.
Although the limbic system is closely related to emotion and social behaviors, little is known about the integrity of limbic pathways and how genetics influence the anatomical abnormalities of limbic networks in children with autism spectrum disorder (ASD). Therefore, we used an ASD twin study design to evaluate the microstructural integrity and autism-related differences in limbic pathways of young children with ASD and to estimate the heritability of limbic tracts microstructure variance. We obtained diffusion tensor imaging scans from 33 pairs of twins with ASD aged 2-9 years and 20 age-matched typically developing children. The ACE model was used to estimate the relative effects of additive genetic factors (A), shared environmental factors (C) and specific environmental factors (E) on the variability of diffusivity measurements. We found a significant decrease in fractional anisotropy (FA) in the bilateral fornix and uncinate fasciculus (UF), as well as increased mean diffusivity (MD) and radial diffusivity (RD) in the bilateral fornix and right UF of ASD children. Correlation analysis showed that FA, MD, and lateralization indices of UF were correlated with autism diagnostic observation schedule scores. The ACE model revealed that genetic effects may drive some of the variability of microstructure in the bilateral fornix, cingulum, and left UF. In conclusion, in children with ASD, there are abnormalities in the white matter microstructure of the limbic system, which is related to the core symptoms; these abnormalities may be related to the relative contribution of genetic and environmental effects on specific tracts. LAY SUMMARY: Autism spectrum disorder (ASD) children have abnormal white matter structure in limbic system related to ASD symptoms, and genetic factors play an important role in the development of limbic tracts.
虽然边缘系统与情绪和社会行为密切相关，但对于边缘通路的完整性以及遗传如何影响自闭症谱系障碍（ASD）儿童边缘网络的解剖结构异常知之甚少。因此，我们使用 ASD 双胞胎研究设计来评估 ASD 儿童的边缘通路的微观结构完整性和与自闭症相关的差异，并估计边缘束微观结构变异的遗传力。我们从 33 对年龄在 2-9 岁的 ASD 双胞胎和 20 名年龄匹配的正常发育儿童中获得了弥散张量成像扫描。使用 ACE 模型来估计加性遗传因素（A）、共享环境因素（C）和特定环境因素（E）对扩散测量值变异性的相对影响。我们发现 ASD 儿童双侧穹窿和钩束的各向异性分数（FA）显著降低，双侧穹窿和右侧钩束的平均扩散系数（MD）和径向扩散系数（RD）增加。相关性分析显示，FA、MD 和钩束的侧化指数与自闭症诊断观察量表评分相关。ACE 模型表明，遗传效应可能导致双侧穹窿、扣带束和左侧钩束的一些微观结构变异性。总之，在 ASD 儿童中，边缘系统的白质微观结构存在异常，与核心症状有关；这些异常可能与遗传和环境因素对特定束的相对贡献有关。
