Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto, Canada.
Am J Psychiatry. 2011 May;168(5):522-9. doi: 10.1176/appi.ajp.2010.10081230. Epub 2011 Mar 1.
Individuals with 22q11.2 deletion syndrome are known to be at high risk of developing schizophrenia. Previous imaging studies have provided limited data on the relation of schizophrenia expression in 22q11.2 deletion syndrome to specific regional brain volumetric changes. The authors hypothesized that the main structural brain finding associated with schizophrenia expression in 22q11.2 deletion syndrome, as for schizophrenia in the general population, would be gray matter volumetric deficits, especially in the temporal lobes.
MR brain images from 29 patients with 22q11.2 deletion syndrome and schizophrenia and 34 comparison subjects with 22q11.2 deletion syndrome and no history of psychosis were analyzed using a voxel-based morphometry method that also yielded volumes for related region-of-interest analyses. The authors compared data from the two groups using an analysis of covariance model correcting for total intracranial volume, age, sex, IQ, and history of congenital cardiac defects. The false discovery rate threshold was set at 0.05 to account for multiple comparisons.
Voxel-based morphometry analyses identified significant gray matter reductions in the left superior temporal gyrus (Brodmann's area 22) in the schizophrenia group. There were no significant between-group differences in white matter or CSF volumes. Region-of-interest analyses showed significant bilateral gray matter volume reductions in the temporal lobes and superior temporal gyri in the schizophrenia group.
The structural brain expression of schizophrenia associated with the highly penetrant 22q11.2 deletion involves lower gray matter volumes in temporal lobe regions. These structural MRI findings in a 22q11.2 deletion syndrome form of schizophrenia are consistent with those from studies involving schizophrenia samples from the general population. The results provide further support for 22q11.2 deletion syndrome as a genetic subtype and as a useful neurodevelopmental model of schizophrenia.
患有 22q11.2 缺失综合征的个体患精神分裂症的风险很高。先前的影像学研究提供了有限的数据，说明 22q11.2 缺失综合征中精神分裂症的表达与特定区域脑体积变化的关系。作者假设，与 22q11.2 缺失综合征中精神分裂症表达相关的主要结构脑发现，就像一般人群中的精神分裂症一样，将是灰质体积缺陷，特别是在颞叶。
使用基于体素的形态测量法分析了 29 名患有 22q11.2 缺失综合征和精神分裂症的患者和 34 名患有 22q11.2 缺失综合征且无精神病病史的对照者的磁共振脑图像，该方法还提供了相关感兴趣区域分析的体积。作者使用协方差分析模型比较了两组数据，该模型校正了总颅内体积、年龄、性别、智商和先天性心脏缺陷史。为了考虑多重比较，假发现率阈值设置为 0.05。
基于体素的形态测量分析确定了精神分裂症组左侧优势颞上回（Brodmann 区 22）的灰质减少。两组间在白质或 CSF 体积方面无显著差异。感兴趣区域分析显示精神分裂症组颞叶和颞上回双侧灰质体积减少。
与高穿透性 22q11.2 缺失相关的精神分裂症的结构脑表达涉及颞叶区域的灰质体积较低。22q11.2 缺失综合征形式的精神分裂症的这些结构 MRI 发现与涉及一般人群精神分裂症样本的研究结果一致。结果为 22q11.2 缺失综合征作为遗传亚型和作为精神分裂症的有用神经发育模型提供了进一步的支持。
