脑结构形态学改变是精神分裂症的遗传内表型

目的 通过对首发精神分裂症患者及其未患病同胞的磁共振成像脑结构分析,探讨遗传因素对脑结构改变的影响程度,为发现精神分裂症的遗传内表型提供实验依据.方法 采用优化的基于体素的形态学研究方法对15例首发精神分裂症患者、19名首发精神分裂症患者未患病同胞及38名正常对照的大脑磁共振图像进行处理,采用一般线性模型进行统计分析.结果 与正常对照组相比,患者组在双侧颢叶、双侧枕叶、左侧岛叶、左侧额叶额上回及右豆状核苍白球灰质有明显减少;在双侧顶叶及双侧边缘叶扣带回灰质增加;未患病同胞组在右侧颞叶、双侧枕叶、左侧岛叶及左侧额叶中央前回等区域灰质明显减少;在左侧顶叶及双侧小脑后叶灰质增加.患者较同胞左侧顶叶楔前叶灰质有增加,未发现两者其他区域存在明显差异.结论 精神分裂症患者及其同胞存在相似的脑结构异常,遗传因素可能是导致精神分裂症脑结构异常的重要因素,提示脑结构形态学改变是精神分裂症的遗传内表型.

Brain structure abnormality as genetic endophenotype of schizophrenia

Objective To explore the role of genetic factors in the brain structural variation by using magnetic resonance imaging scan in schizophrenic patients and their unaffected siblings, and to provide experimental evidence for identifying endophenotype of schizophrenia. Methods The optimized voxel-based morphometry (OVBM) was used to process the brain magnetic resonance images in 15 first episode drug-naive schizophrenic patients, 19 unaffected siblings of the patients and 38 normal control subjects. The data were analyzed by using general linear model. Results Compared to the normal control subjects, significant decreases of gray matter was observed in first episode drug-naive schizophrenia in bilateral temporal lobe,bilateral occipital lobe, left insula, left frontal lobe superior frontal gyrus and right lentiform nucleus medial globus pallidus. Significant increases of gray matter in bilateral parietal lobe, bilateral limbic lobe cingulate gyrus in patients group while compared to controls were also found. In unaffected siblings, significant decreases of gray matter was observed in the right temporal lobe, bilateral occipital lobe, left insula, and left frontal lobe precentral gyrus, and significant increases of gray matter were found in left parietal lobe and bilateral cerebellum posterior lobe. Increased gray matter in left parietal lobe precuneus was found in first episode drug-naive schizophrenia when compared with their unaffected siblings. Conclusion There were similar brain structure abnormalities between the first episode drug-naive schizophrenia and their unaffected siblings. Genetic factor may play important role in brain structural abnormality in schizophrenia, which suggested that the brain structural change might be a genetic endophenotype of schizophrenia.