Savic I, Arver S
Department of Women's and Children's Health, division of Pediatric Neurology, Neurology Clinic, Karolinska Hospital, Stockholm, Sweden.
Department of Medicine, Karolinska Institutet, Stockholm, Sweden.
Cereb Cortex. 2014 Dec;24(12):3246-57. doi: 10.1093/cercor/bht180. Epub 2013 Aug 7.
Although it has been shown that cortical thickness (Cth) differs between sexes, the underlying mechanisms are unknown. Seeing as XXY males have 1 extra X chromosome, we investigated the possible effects of X- and sex-chromosome dosage on Cth by comparing data from 31 XXY males with 39 XY and 47 XX controls. Plasma testosterone and estrogen were also measured in an effort to differentiate between possible sex-hormone and sex-chromosome gene effects. Cth was calculated with FreeSurfer software. Parietal and occipital Cth was greater in XX females than XY males. In these regions Cth was inversely correlated with z-normalized testosterone. In the motor strip, the cortex was thinner in XY males compared with both XX females and XXY males, indicating the possibility of an X-chromosome gene-dosage effect. XXY males had thinner right superior temporal and left middle temporal cortex, and a thicker right orbitofrontal cortex and lingual cortex than both control groups. Based on these data and previous reports from women with XO monosomy, it is hypothesized that programming of the motor cortex is influenced by processes linked to X-escapee genes, which do not have Y-chromosome homologs, and that programming of the superior temporal cortex is mediated by X-chromosome escapee genes with Y-homologs.
尽管已有研究表明皮质厚度（Cth）存在性别差异，但其潜在机制尚不清楚。鉴于XXY男性多一条X染色体，我们通过比较31名XXY男性与39名XY男性及47名XX女性的数据，研究了X染色体和性染色体剂量对Cth的可能影响。我们还测量了血浆睾酮和雌激素，以区分可能的性激素和性染色体基因效应。使用FreeSurfer软件计算Cth。XX女性的顶叶和枕叶Cth大于XY男性。在这些区域，Cth与z标准化睾酮呈负相关。在运动皮层，XY男性的皮层比XX女性和XXY男性都薄，这表明存在X染色体基因剂量效应的可能性。与两个对照组相比，XXY男性的右侧颞上回和左侧颞中回皮层较薄，而右侧眶额皮层和舌回皮层较厚。基于这些数据以及先前关于XO单体女性的报道，推测运动皮层的编程受与X逃逸基因相关过程的影响，这些基因没有Y染色体同源物，而上颞叶皮层的编程由具有Y同源物的X染色体逃逸基因介导。
