PDF(Pubmed)
Abstract：
Twin studies have found gross cerebellar volume to be highly heritable. However, whether fine-grained regional volumes within the cerebellum are similarly heritable is still being determined. Anatomical MRI scans from two independent datasets (QTIM: Queensland Twin IMaging, N = 798, mean age 22.1 years; QTAB: Queensland Twin Adolescent Brain, N = 396, mean age 11.3 years) were combined with an optimised and automated cerebellum parcellation algorithm to segment and measure 28 cerebellar regions. We show that the heritability of regional volumetric measures varies widely across the cerebellum ( h 2 $$ {h}^2 $$ 47%-91%). Additionally, the good to excellent test-retest reliability for a subsample of QTIM participants suggests that non-genetic variance in cerebellar volumes is due primarily to unique environmental influences rather than measurement error. We also show a consistent pattern of strong associations between the volumes of homologous left and right hemisphere regions. Associations were predominantly driven by genetic effects shared between lobules, with only sparse contributions from environmental effects. These findings are consistent with similar studies of the cerebrum and provide a first approximation of the upper bound of heritability detectable by genome-wide association studies.
摘要：
双胞胎研究发现，小脑的总体积具有高度遗传性。然而,小脑内的细粒度区域体积是否具有类似的遗传性仍在确定中。来自两个独立数据集的解剖MRI扫描(QTIM：昆士兰双胞胎成像，N=798，平均年龄22.1岁；QTAB：昆士兰双胞胎青少年大脑，N=396，平均年龄11.3岁）与优化和自动化的小脑分割算法相结合，以分割和测量28个小脑区域。我们表明，区域体积测量的遗传力在小脑中差异很大(h2$${h}^2$$47%-91%)。此外,QTIM参与者子样本的良好至优异的重测可靠性表明,小脑体积的非遗传方差主要是由于独特的环境影响而非测量误差.我们还显示了同源左半球和右半球区域体积之间强烈关联的一致模式。关联主要是由小叶之间共有的遗传效应驱动的，只有很少的环境影响。这些发现与类似的大脑研究一致，并提供了全基因组关联研究可检测的遗传力上限的第一个近似值。
