精神分裂症高发家系和散发患者的分子遗传基础研究

Schizophrenia, with significant genetic tendency, is one of the seriously chronic diseases that jeopardize human health. However, the molecular genetic mechanism underlying the disease remains unknown. In our previous work, we established a bio-bank containing the genetic samples from more than 500 schizophrenia patients including the ones from 6 high-incidence pedigrees. Performing whole exome sequencing, we have collected the genomic data from all the 6 families. Genomic analysis was accomplished for one of them and ATRN was chosen as the most possible pathogenic/susceptible gene that was linked to the disease. Employing CRISPR/Cas9 technology, we made a knockout zebrafish model carrying presumptively null alleles of atrn, the orthologous gene of human ATRN. Based on the preliminary results, we will figure out the mutated genes that co-segregated with the schizophrenia by continuously doing genomic analyses on the other 5 families whose whole exomes had been sequenced. In the meantime, we will do data mining from the published literatures to collect the pathogenic/susceptible genes for schizophrenia. By combining the gene sets from the literatures and the high-incidence pedigrees, we will design and make a gene detection chip for detecting the mutations of pathogenic/susceptible genes for schizophrenia. With the gene detection chip, we will scan the genomes of sporadic patients. The data obtained from the scanning will be used to study the causing effect of the susceptible genes on schizophrenia and to create a risk model for predicting the possibilities of a subject to suffer from schizophrenia. Additionally, we will select 2-3 susceptible genes with high effect on the disease from the susceptible genes to make genome edited zebrafish models. By exploring whether the genome edited models together with atrn knockout zebrafish model will show similar behavior changes to the schizophrenia patients, whether the mutated zebrafish have abnormal brain development or have deformed structure and function of brains, we will identify the roles of susceptible genes in schizophrenia and provide the evidences for revealing the molecular genetic mechanism underlying schizophrenia.

精神分裂症是具高遗传倾向的重大慢病，但迄今分子遗传基础不明。在前期工作中，我们建立了超过500例的精神分裂症样本库；对所含6个高发家系进行了全外显子组测序；完成了其中1个家系的基因组学研究；优选其中1个与疾病共分离的突变基因ATRN，制备了斑马鱼基因敲除模型。本研究将在前期工作基础上，对其余5个高发家系继续进行基因组学研究，确定与疾病共分离的突变基因；同时检索已报道的精神分裂症易感基因，整合两个基因集设计基因检测芯片；通过对散发患者基因组进行扫描，研究易感基因在精神分裂症发生中的贡献度，初步建立疾病风险预测模型；优选2-3个高贡献度的易感基因制备斑马鱼基因组编辑模型，连同已建立的atrn敲除斑马鱼模型，研究基因突变是否可导致斑马鱼出现与精神分裂症患者相似的行为学异常，是否影响脑发育以及成年动物脑结构和功能，确认突变基因在精神分裂症发生中的作用，为揭示精神分裂症的分子遗传基础提供初步依据。

精神分裂症是一种高度遗传的神经发育性脑疾病，其发病的器质性变化及分子遗传机制尚不清楚。我们对精神分裂症家系和散发患者开展基因组测序研究鉴定高贡献度基因突变，构建基因敲除斑马鱼模型进行功能分析，最后通过进一步的临床表型分析进行验证，从而发现精神分裂症发生的可能机制，具体结果和意义如下。.我们利用全外显子测序对6个高发家系进行了检测与分析，鉴定出3个精神分裂症重点候选基因（ATRN、SORL1和KIF26A）。完成了506例散发患者的全外显子组扫描，统计分析了家系候选基因与已报道精神分裂症相关基因在散发患者中突变携带情况，这一结果验证了家系分析的发现，同时为揭示散发患者基因组层面的病因提供参考。此外，通过患者—正常对照关联分析鉴定出10个散发患者显著富集的基因/突变，这一结果提示这些基因可能为新的候选精神分裂症易感基因。.我们对ATRN基因进行了功能研究，评估ATRN与精神分裂症之间的关系，制作了atrn敲除斑马鱼系并分析它们的行为模式，结果表明atrn功能缺失导致成鱼的攻击行为增加，幼鱼的一般运动更加活跃，与精神分裂症的阳性症状相吻合。转录组分析结果表明，睾酮合成途径中cyp51和hsd17b7的表达在atrn功能缺失以后直接导致睾酮合成通路的关键基因的表达水平升高，进而导致睾酮含量的升高，引起斑马鱼运动的异常活跃和攻击行为增加。.通过进一步的临床分析，我们发现男性精神分裂症患者有更高的比例表现出睾酮水平低，而女性患者相反；我们还分析了患者中携带ATRN有害突变的组别与未携带组别的差异，结果显示男性患者中携带组有更高的比例表现出睾酮水平低，而女性患者中携带组有更高的比例表现出睾酮水平高；这一结果提示ATRN可能通过影响睾酮水平参与精神分裂症的发生过程，这为进一步研究精神分裂症与激素水平的关联提供参考。