Biondi A, Nogueira H, Dormont D, Duyme M, Hasboun D, Zouaoui A, Chantôme M, Marsault C
Department of Neuroradiology, Pitié-Salpêtrière Hospital, University Paris VI, France.
AJNR Am J Neuroradiol. 1998 Aug;19(7):1361-7.
The role of genetic mechanisms and the influence of environmental events in human brain development have been difficult to evaluate. The purpose of this study was to compare the cerebral cortical morphology and midline structures of monozygotic twin pairs using MR imaging.
Six observers, blinded to twin pairings, evaluated the 3-D renderings of the cortical surface and midline structures from MR images of seven monozygotic twin pairs. A morphometric analysis of the corpus callosum and of the distance between the anterior and posterior commissures was also performed.
Despite surprising anatomic differences, the brains of the twin pairs were similar enough to enable the observers to distinguish twin pairs from unrelated subjects. Five of six observers correctly identified the brains of all seven twin pairs; the remaining observer failed to make a correct match in only one of seven pairs. Three of six observers identified the midline sagittal images of the related twins in all seven pairs, and the other three identified the related midline sagittal images in five of seven pairs. The results were statistically significant.
Although the observed differences in morphologic characteristics between twins necessarily reflect nongenetic influences, the cortical patterns and midline structures of monozygotic twins probably are genetically similar.
遗传机制的作用以及环境因素对人类大脑发育的影响一直难以评估。本研究的目的是利用磁共振成像（MR成像）比较同卵双胞胎对的大脑皮质形态和中线结构。
六位观察者在不知双胞胎配对情况的前提下，对七对同卵双胞胎的MR图像的皮质表面和中线结构的三维渲染图进行评估。还对胼胝体以及前后连合之间的距离进行了形态计量分析。
尽管存在令人惊讶的解剖学差异，但双胞胎对的大脑仍足够相似，使观察者能够将双胞胎对与无关个体区分开来。六位观察者中有五位正确识别了所有七对双胞胎的大脑；其余一位观察者仅在七对中的一对中未能做出正确匹配。六位观察者中有三位识别出了所有七对相关双胞胎的中线矢状面图像，另外三位在七对中的五对中识别出了相关的中线矢状面图像。结果具有统计学意义。
尽管观察到的双胞胎之间形态特征差异必然反映了非遗传影响，但同卵双胞胎的皮质模式和中线结构可能在遗传上相似。
