基因拷贝数变异与智力障碍病因学研究进展

基因拷贝数变异(copy number variations,CNVs)是指DNA片段大小从1 kb至Mb的亚微观结构变异,已成为探讨与疾病相关遗传变异的研究热点,特别是神经认知系统的遗传病,如精神分裂症、智力障碍等综合征、本文综述了基因拷贝数变异与智力障碍的关联关系和基因拷贝数变异检测技术进展在智力障碍诊断中的应用,这对揭示智力障碍发病机制有着重要意义.     

基因拷贝数变异与智力障碍病因学研究进展

基因拷贝数变异(copy number variations,CNVs)是指DNA片段大小从1 kb至Mb的亚微观结构变异,已成为探讨与疾病相关遗传变异的研究热点,特别是神经认知系统的遗传病,如精神分裂症、智力障碍等综合征、本文综述了基因拷贝数变异与智力障碍的关联关系和基因拷贝数变异检测技术进展在智力障碍诊断中的应用,这对揭示智力障碍发病机制有着重要意义.     

265例不明原因智力障碍遗传学病因分析研究

目的对265例不明原因智力障碍拷贝数变异高发区16p11.2、16p13.11、15q11.2的四个智障候选基因AL-DOA、TBX6、CYFP1、Nde1进行探索性遗传学分析。方法结合G-显带染色体核型分析与多重连接依赖性探针扩增技术筛出不明原因智力障碍患者,并建立多重PCR对不明原因智障患者进行遗传学病因分析。结果 265例不明原因智力障碍病例中发现1例基因Nde1基因拷贝数缺失。结论本文建立的多重PCR检测基因突变的方法简便、经济,可对不明原因智力障碍患者进行智障高发突变基因进行初步遗传学筛查,为深入研究先天性智力障碍病因机制奠定了基础。     

一例双着丝粒染色体患儿的临床病因分析并文献复习

目的探讨基因拷贝数变异与临床表型的关系,同时探讨微阵列比较基因组杂交技术在细胞分子遗传学诊断中的优越性。方法对一例智力障碍、语言发育障碍的患儿行G显带染色体核型分析和拷贝数变异的检测,同时行家系的相关研究,并对已报道的相关综合征进行文献复习。结果患儿父母的染色体未见明显异常,患儿的染色体核型为:45,XY,psu?dic(9;12)(p24;p13)dn,拷贝数检测结果为:arr9p24.3p23(244,457-10,315,723)×3,12p13.3(191,619-1,429,503)×1。结论该患儿的临床表型与其基因拷贝数的变异相关联,微阵列分析技术能够快速诊断出基因组的微失衡,具有高分辨率和高准确性的优点,是不明原因智力障碍患儿遗传学诊断的重要技术。     

智力障碍患儿ARX基因起始密码c. 1A>G变异的遗传学分析

目的对1例智力障碍患儿进行基因变异分析,明确其遗传学病因。方法对1例智力障碍患儿进行目标区域捕获测序,将测序结果与GenBank提供的标准序列进行对比,寻找基因序列的变异。对于检出的可能致病性变异,应用Sanger测序法,对患儿双亲进行验证,并分析患儿的临床遗传学特点。结果检测出患儿ARX基因c.1A>G半合子变异;双亲验证后,证实母亲为ARX基因c.1A>G杂合变异携带者,因此患儿的变异遗传自母亲。通过检索公共数据库及本地数据库该变异未收录、也未见文献报道,ARX基因c.1A>G变异为未报道过的新变异,临床意义为“可能致病性变异”。结论AKX基因c.1A>G(pMetl?)变异可能与患儿的智力障碍的发生相关。     

人肝癌细胞系HepG2和Huh7中的基因组拷贝数变异分析

目的 利用人肝细胞癌拷贝数变异和转录组实验，结合临床公共数据，探索肝细胞癌的拷贝数变异对肝癌发生发展的影响。方法 用光学基因组图谱技术识别肝癌细胞系HepG2和Huh7中的拷贝数变异，随后分析两种细胞系拷贝数变异基因的功能，并根据富集通路绘制蛋白质相互作用网络。选取两个细胞系核心网络中的关键基因，分析肝细胞癌拷贝数变异与基因表达之间的关系。GEPIA数据库分析基因表达与患者临床生存的关系。用RNA-seq实验和公共数据验证基因的表达水平。结果 HepG2细胞主要存在拷贝数增加，相关基因富集在雌激素信号通路、金黄色葡萄球菌感染等通路；Huh7细胞系中既有拷贝数增加又有减少，相关基因主要富集嗅觉传导、细胞因子-细胞因子受体相互作用等通路。关键基因SRC、MAPK3和MAP3K7拷贝数与基因表达成正比，并且高表达这些基因的患者生存期显著降低(P<0.05)。相比于HEK293T细胞系，SRC、MAP3K7基因在两个肝癌细胞系的表达显著升高(P<0.001),提示了肝细胞癌的特异性变异，MAPK3无差异。结论 肝细胞癌拷贝数变异基因SRC、MAP3K7的表达与患者的预后显著相关，可...     

CHAMP1基因变异所致常染色体显性智力障碍40型患儿1例的分析

目的探讨1例CHAMP1基因变异所致常染色体显性智力障碍40型(MRD40)患儿的临床表型和遗传学特征。方法选取2019年10月至2020年9月于郑州大学第一附属医院就诊的1例MRD40型患儿为研究对象。采集患儿的临床资料, 用低深度高通量全基因组拷贝数变异测序(CNV-seq)和全外显子组测序(WES)对其进行遗传学分析, 并回顾文献报道的CHAMP1基因变异所致MRD40病例的临床表型和遗传学特征。结果患儿, 女, 11月龄, 表现为全面发育迟缓合并特殊面容。CNV-seq检测未见异常, WES结果提示其携带CHAMP1基因c.1908C>G(p.Y636*)新发杂合变异。连同12篇文献报道的33例患儿, 除发育迟缓、智力障碍外, 大多存在肌张力减退(94.1%)、说话和/或行走时间延迟(85.2%, 82.4%)及眼部异常(79.4%)。共检出CHAMP1基因变异26个, 大多为功能缺失变异, 位于第3外显子且为新发。结论 CHAMP1基因c.1908C>G(p.Y636*)杂合变异可能是本例患儿的致病原因。对于全面发育迟缓/智力障碍、肌张力减退伴特殊面容的患儿, 应...     

全外显子组测序诊断1例罕见Chung-Jansen综合征

目的 探究1例智力障碍、发育迟缓患儿的致病原因。方法 患儿应用全外显子组测序技术（WES）和染色体拷贝数变异技术（CNV）筛选可疑致病性变异点,对家系采用Sanger测序方法对变异位点进行验证。结果 患儿CNV检测未发现100 kb以上已知的、明确致病的基因组拷贝数变异（CNVs）和染色体非整倍体,WES检测发现6q14.1染色体上PHIP基因（NM＿017934.7:exon22:c.2537G>C:p.S846T）杂合错义突变,未见文献报道,父母均未携带此突变,根据美国医学遗传学与基因组学学会（ACMG）指南,PHIP基因c.2537G>C突变判断为疑似致病突变位点（PM2+PM6+PP2+PP3）。结论 PHIP基因c.2537G>C是导致患儿Chung-Jansen综合征疾病的原因,属于国内首例报道Chung-Jansen综合征疾病,为疾病临床诊断提供依据,在一定程度上补充了遗传学领域资料。     

一个汉族自闭症谱系障碍家系的拷贝数变异分析

目的 对一个中国汉族自闭症谱系障碍(autistic spectrum disorder,ASD)家系进行拷贝数变异(copy number variation,CNV)的分析.方法 该家系共3例患者.建立家系成员EB病毒转染永生化的B淋巴细胞系,并提取基因组进行核型分析与Affymatrix 500k SNP芯片检测,所获结果由Genotyping Console与GeneChip(R)Chromosome Copy Number Analysis Tool软件分析,采用家系中3名正常儿童作为对照,对患者中的拷贝数变异进行分析.结果 核型分析未发现染色体变异情况,而15q11位点在患者中都存在拷贝数变异,其中物理位置为19827281-19998230的片段出现了拷贝数减少,含有OR11K1P、OR4Q1P、OR4H6P、OR4M2、OR4N3P等基因,而另外3条分别为37 kb、1316 kb、37 kb的片段则出现了拷贝数增加,含有LOC388079、LOC441709等基因.结论 位于这一拷贝数变异位点上有OR11K1P、OR4Q1P、OR4H6P、OR4M2等嗅觉受体基因,也有功能未明的LOC388079基因,为自闭症的遗传机理研究提供了新的提示.     

一例15号额外标记染色体的遗传学分析

目的 探讨15q11-13拷贝数增加与智力障碍、语言发育落后及孤独症等表型的关系并探讨细胞遗传学技术与分子遗传学技术相结合进行诊断的可行性及优越性.方法 应用常规G显带染色体核型分析技术、多重连接依赖性探针扩增技术及微阵列比较基因组杂交技术对1例额外标记染色体进行遗传学分析.结果 患者核型为47,XY,+mar.多重连接依赖性探针扩增技术结果显示额外标记染色体来源于15号染色体,并存在母源性拷贝数复制增加.微阵列比较基因组杂交显示基因组拷贝数变异区域为15q11-13,大小9.8 Mb,基因位点:20477397～30298155.结论 15q11-13区域拷贝数复制增加与患者语言发育落后、智力低下及孤独症等临床表现密切相关.传统的细胞遗传学分析技术与微阵列比较基因组杂交技术相结合,有利于检测结果的相互补充与验证,从而获得更为精确的遗传学数据,为进一步研究染色体畸变、基因组重排与临床表型的关系奠定了基础.     

A STUDY ON CNV OF PATIENTS WITH MENTAL RETARDATION

Objective:To investigate the variations of contingent negative variation(CNV)of petientswith mental retardation.Methods:The CNV was recorded in 16 children with mental retardation(MR)and 14healthly age-matched controls.And CNV retest was carried out in 11 children with MR after one yeat treatment ofPiracetam.Results:Compared with the normal control,the CNV of MR group showed prolonged postimperativenegative variation(PINV)duration(P<0.01)and total A-C duration(P<0.01),decreased amplitude B(P<0.01),and reduced preimperative A-S2 area(P<0.01).A comparison of the CNV of MR group was made be-tween before and after one year treatment of Piracetam and no significant difference was found.Conclusions:The significant CNV variations were found in children with MR and these abnormal changes presisted throughoutthe Piracetam treatment.     

Molecular karyotyping of patients with unexplained mental retardation by SNP arrays: A multicenter study

Genomic microarrays have been implemented in the diagnosis of patients with unexplained mental retardation. This method, although revolutionizing cytogenetics, is still limited to the detection of rare de novo copy number variants (CNVs). Genome‐wide single nucleotide polymorphism (SNP) microarrays provide high‐resolution genotype as well as CNV information in a single experiment. We hypothesize that the widespread use of these microarray platforms can be exploited to greatly improve our understanding of the genetic causes of mental retardation and many other common disorders, while already providing a robust platform for routine diagnostics. Here we report a detailed validation of Affymetrix 500k SNP microarrays for the detection of CNVs associated to mental retardation. After this validation we applied the same platform in a multicenter study to test a total of 120 patients with unexplained mental retardation and their parents. Rare de novo CNVs were identified in 15% of cases, showing the importance of this approach in daily clinical practice. In addition, much more genomic variation was observed in these patients as well as their parents. We provide all of these data for the scientific community to jointly enhance our understanding of these genomic variants and their potential role in this common disorder. Hum Mutat 30:1–11, 2009. © 2009 Wiley‐Liss, Inc.     

A 15q13.3 microdeletion segregating with autism

Autism and mental retardation (MR) show high rates of comorbidity and potentially share genetic risk factors. In this study, a rare ∼2 Mb microdeletion involving chromosome band 15q13.3 was detected in a multiplex autism family. This genomic loss lies between distal break points of the Prader–Willi/Angelman syndrome locus and was first described in association with MR and epilepsy. Together with recent studies that have also implicated this genomic imbalance in schizophrenia, our data indicate that this CNV shows considerable phenotypic variability. Further studies should aim to characterise the precise phenotypic range of this CNV and may lead to the discovery of genetic or environmental modifiers.     

The Abilities of Children With Mental Retardation to Remember Personal Experiences: Implications for Testimony

Investigated the abilities of children with mental retardation to remember the details of a personally experienced event. A simulated health check was administered to 20 children with mental retardation and 40 normally developing children, half matched on mental age (MA) and half matched on chronological age (CA) with the children with mental retardation. The children's memory was assessed immediately after the health check and 6 weeks later. Overall, the children with mental retardation accurately recalled the health check features, provided detail, and resisted misleading questions about features that did not occur. The group with mental retardation performed similarly to the MA matches on virtually all of the memory variables. The children with mental retardation performed worse than the CA matches on most of the memory variables, although they were able to recall a similar number of features. The findings are discussed in terms of the ability of children with mental retardation to provide accurate testimony.     

精神发育迟滞患儿的智力及其影响因素分析

目的　探讨精神发育迟滞患儿智力的影响因素并对其进行分析。方法　对 71例精神发育迟滞患儿行韦氏儿童智力量表、CT及脑电图等检查 ,并收集其相关病史资料。结果　多元逐步回归分析结果 ,共筛选出对智商影响有意义的因素 3个 ,依次为脑电图、中枢神经系统疾病史、窒息史。结论　脑电图在了解智力障碍方面要优于 CT,轻度精神发育迟滞患儿常以中枢神经系统疾病为主 ,产伤 (窒息史 )仍是引起精神发育迟滞最常见的原因之一     

大连市城区启智学校学生智力低下的影响因素分析

目的 了解大连市启智学校学生智力低下的影响因素,以寻求有效的预防与干预措施.方法 通过向学生家长发放问卷的形式调查.结果 智力低下致病原因不明者占37.82%,可能与性别及发现智力问题的时间有关;明确致病因素中位居前3位的依次是:脑部疾病(占17.66%)、先天愚型与新生儿窒息(各占7.14%).结论 提高预防水平,减少导致智力低下的高危因素,降低智力低下儿童的出生率;对于已被确诊为智力低下的儿童尽早实施干预与治疗.     

Event Related Potentials and Time Estimation

Event related potentials (ERPs) recorded from the scalp of man were studied during a time estimation task. The principal ERP correlate of mental activity associated with time estimation appeared to be a CNV wave followed by a late positive shift. Latency of CNV termination was correlated with temporal judgments. There was some evidence that the onset of CNV termination occurred prior to the estimated time of occurrence of cortical motor command signals associated with production of the temporal judgments.