一个遗传性非综合征型耳聋大家系的GSDME基因突变分析

目的 利用二代测序技术(next-generation sequencing,NGS)结合Sanger测序验证对一听力障碍的家系进行致病基因检测.方法 以2018年广东省妇幼保健院产前诊断科诊断为听力障碍的一家系为研究对象,采集先证者病史、听力检查结果及家族史,采用遗传性耳聋精选基因检测包对先证者进行基因检测,后对发现...     

无创产前检测在高龄孕妇中检测胎儿非整倍体的临床应用

目的:探讨高通量测序(HTS)技术在高龄孕妇胎儿染色体非整倍体筛查中的临床应用。方法:2 090例单胎高龄孕妇行无创产前检测(NIPT),结果异常的孕妇再行羊膜腔穿刺,羊水细胞培养后染色体G320显带核型分析。结果:2 090例样本中,高通量基因测序提示22例胎儿染色体非整倍体高风险,19例孕妇自愿接受羊水产前诊断,其中16例羊水G带核型结果与NIPT测序结果一致,包括12例T21,2例T18,2例性染色体异常,阳性预测值为84.2%(16/19)。结论:对于拒绝接受介入性产前诊断的高龄孕妇,临床可推荐无创的高通量基因测序产前检测技术,进一步降低出生缺陷儿的发生率。     

卵巢早衰的遗传学研究进展

卵巢早衰(POF)是一种临床高度异质且病因复杂的疾病,遗传因素是其重要的发病原因。遗传因素主要包括X染色体、常染色体异常、微小RNA表达异常等。全基因组关联研究(GWAS)、高通量测序(NGS)技术等迅猛发展,可对基因标志物或核苷酸多态性进行统计分析,发现其间的内部联系,揭示新的致病基因,为POF的遗传学基础研究提供崭新的平台。     

染色体易位-胚胎植入前诊断的研究进展

染色体易位携带者有较高的发生不良妊娠结局的风险,主要源自高概率的非均衡配子。对于染色体易位的携带者,进行胚胎植入前遗传学诊断(preimplantation genetic diagnosis,PGD)可以改善妊娠结局。目前,临床应用的非平衡易位诊断的方法主要有比较基因组杂交微阵列(comparative genomic hybridization array,array CGH)、单核苷酸多态性微阵列(single nucleotide polymorphism array,SNP array)和二代测序(next generation sequencing,NGS);荧光原位杂交(fluorescence in situ hybridization,FISH),能够区分平衡易位和正常胚胎,可能实现的技术有NGS。此外,平衡易位的诊断是否有必要开展尚存在争议。     

拷贝数变异测序在染色体易位夫妇植入前遗传学诊断中的临床应用

目的探讨拷贝数变异测序(copy number variation sequencing, CNV-seq)用于染色体易位夫妇胚胎植入前诊断的应用价值。 方法回顾性分析2017年1月至2018年12月,在广东省妇幼保健院生殖健康与不孕症科进行植入前遗传学诊断(preimplantation genetic diagnosis,PGD)的211对染色体易位夫妇患者的临床病例。使用CNV-seq对胚胎染色体进行检测,并对患者一般信息和PGD结果进行分析。 结果1210个胚胎中,被检出837个(79.2%)胚胎存在染色体异常,373个(30.8%)胚胎为整倍体。在241个PGD周期中,68个(27.6%)周期所有胚胎均存在染色体异常,178个(72.4%)周期至少含有一个整倍体胚胎。在176个移植周期中,130个(73.9%)确定临床妊娠,已出生46个健康婴儿,12例发生早期流产。 结论CNV-seq可准确地区分胚胎染色体是否存在异常,避免因胚胎含有染色体异常而被移植,是一种可靠而准确的PGD技术。     

基因测序技术在生殖领域的应用进展

基因测序技术自被发明以来在生命科学领域的研究中发挥着重要作用,利用测序技术对辅助生殖技术(ART)后代进行基因水平检测来评估ART的安全性,是一种非常有效的手段。而利用测序技术对植入前胚胎进行基因检测,不仅可以进行非整倍体筛查来选择优质胚胎进行移植,提高胚胎种植率,还可以避免遗传性疾病在家系内的传递;另外,利用测序技术对不孕不育患者进行基因方面检测,从而发现一些高敏感的致病基因,对于了解不孕不育疾病机理、发现治疗方案提供新的思路。     

基因组时代产前诊断面临的机遇和挑战

        自20世纪70年代开始,染色体核型分析技术作为诊断胎儿染色体异常的金标准已使用多年,但该技术存在分辨率较低（5~10Mb）、培养周期长、检测通量低及有培养失败风险等局限性。随后,靶向诊断技术（FISH、QF-PCR、MLPA）的出现,大大缩短了检测时间,与染色体核型技术联合应用,可早期诊断常见的胎儿染色体异常。此外,Sanger测序作为基因变异检测的金标准,可用于明确致病的单基因疾病的产前诊断。然而,以上技术均无法实现在全基因组范围内进行快速、高分辨率地诊断胎儿致病性变异。 浏览更多请关注微信公众号及当期杂志。     

低深度全基因组测序技术在产前诊断中的研究进展

先天性心脏病、多指（趾）、唇裂、先天性脑积水及马蹄内翻足在出生缺陷患儿疾病中位居前5位,有报告指出上述疾病的发生与染色体的微缺失、微重复异常有关。产前诊断是预防出生缺陷的主要手段,是在胎儿出生前利用先进技术对胎儿的先天性疾病进行诊断。研究表明低深度全基因组测序技术（copy number variation sequencing,CNV-seq）可对产前染色体微缺失、微重复异常进行诊断,将染色体异常的检出率增加至2.8%。CNV-seq技术是在高通量测序基础上发展的全基因组测序技术,其检测范围广、分辨率高,可检测全基因组水平的微缺失、微重复异常,已逐步应用于胎儿先天性疾病及流产组织遗传学病因的检测,还可用于明确未知来源的染色体畸变。综述CNV-seq技术在产前诊断中的研究进展。     

高通量测序技术检测自然流产绒毛样本的染色体拷贝数变异情况

目的探讨高通量测序(NGS)技术在检测自然流产绒毛样本的遗传学分析准确性和异常结果检出率中的应用价值。方法选取早期自然流产患者的绒毛组织作为研究对象,采用NGS方法对流产绒毛组织的染色体拷贝数变异情况进行检测。同时,我们采用比较基因组杂交芯片(a-CGH)法进行验证,以确保NGS检测结果的准确性。结果本研究共纳入256例绒毛样本,检测成功率100%。染色体异常共计145例(56.64%),染色体未见明显异常共计111例(43.36%)。染色体微缺失/微重复共34例(13.28%)。在染色体异常结果中,非整倍体128例(50%),其中三体共计94例(36.72%),主要涉及22号和16号染色体,占三体总例数的50%;单体共24例(9.37%),Turner综合征为22例(91.7%);四体共10例(3.91%)。染色体结构异常共17例(6.64%)。随机选取的5例样本同时采用a-CGH芯片检测,结果与高通量测序结果一致。结论 NGS技术是一项敏感、高效的遗传学检测手段,可有助于明确自然流产的遗传学因素,以期指导下次妊娠。     

重视植入前遗传学诊断中心的组织管理

正植入前遗传学诊断(PGD)技术主要应用于面临妊娠遗传性疾病胎儿高风险的夫妇。遗传性疾病包括所有的单基因遗传病、X连锁隐性遗传病、染色体平衡易位等,避免或降低其因妊娠异常胎儿须面临的终止妊娠风险。目前PGD相对于其他的诊断技术,缺乏统一的规范和标准。欧美更多的地区开始为提供PGD检测的实验室实施认证。PGD因其费用昂贵、流程复杂、技术要求高,需要更严格的组织管理,包括适应证的严格控制。临     

Third-generation sequencing: any future opportunities for PGT?

PurposeTo investigate use of the third-generation sequencing (TGS) Oxford Nanopore system as a new approach for preimplantation genetic testing (PGT).MethodsEmbryos with known structural variations underwent multiple displacement amplification to create fragments of DNA (average ~ 5 kb) suitable for sequencing on a nanopore.ResultsHigh-depth sequencing identified the deletion interval for the relatively large HBA1/2--SEA alpha thalassemia deletion. In addition, STRs were able to be identified in the primary sequence data for potential use in conventional PGT-M linkage confirmation. Sequencing of amplified embryo DNA carrying a translocation enabled balanced embryos to be identified and gave the precise identification of translocation breakpoints, offering the opportunity to differentiate carriers from non-carrier embryos. Low-pass sequencing gave reproducible profiles suitable for simple identification of whole-chromosome and segmental aneuploidies.ConclusionTGS on the Oxford Nanopore is a possible alternative and versatile approach to PGT with potential for performing economical workups where the long read sequencing information can be used for assisting in a traditional PGT workup to design an accurate and reliable test. Additionally, application of TGS has the possibility of providing combined PGT-A/SR or in selected stand-alone PGT-M cases involving pathogenic deletions. Both of these applications offer the opportunity for simultaneous aneuploidy detection to select either balanced embryos for transfer or additional carrier identification. The low cost of the instrument offers new laboratories economical entry into onsite PGT.     

Prenatal diagnosis of familial recessive PIGN mutation associated with multiple anomalies: A case report

ObjectiveWe present a novel homozygous splice site mutation in the PIGN gene identified by whole exome sequencing and explored the genotype–phenotype correlation.Case reportA healthy 32-year-old woman underwent an ultrasound at 13 + 5 weeks of gestation. The ultrasound revealed multiple anomalies again including cystic hygroma, omphalocele and a ventricular septal defect. The pregnancy was subsequently terminated, and whole exome sequencing revealed a novel homozygous splice site mutation in the PIGN gene c.963 G > A (p.Gln321Gln). The same variant was also detected by pedigree-based Sanger sequencing in both parents as heterozygous, while they had normal karyotypes.ConclusionOur case report enhances the phenotype–genotype correlation associated with homozygous loss of function mutations in the PIGN gene.     

多次退火环状循环扩增技术在单细胞水平诊断脊髓性肌萎缩症的应用评估

目的:应用并评价多次退火环状循环扩增(multiple annealing and looping-based amplification cycles,MALBAC)技术在单细胞水平诊断脊髓性肌萎缩症(spinal muscular atrophy,SMA)基因变异的效率。方法:收集SMN1基因7号外显子纯合缺失、正常皮肤成纤维细胞以及废弃胚胎单个卵裂球细胞,分别使用MALBAC和多重链置换扩增(multiple displacement amplification,MDA)方法进行全基因组扩增(WGA)。Sanger测序检测SMN1及SMN2序列,并对3个微卫星位点进行连锁分析。结果:2种扩增技术的总扩增成功率、等位基因脱扣(ADO)率无统计学差异(P0.05);MALBAC组诊断准确率为91.7%(67/73),低于MDA组的96.1%(73/76)(P0.05)。结论:针对SMA疾病开展单细胞水平遗传学诊断,传统MDA方法略优于MALBAC全基因组扩增技术。     

Genetic basis of acephalic spermatozoa syndrome,and intracytoplasmic sperm injection outcomes in infertile men: a systematic scoping review

PurposeAcephalic spermatozoa syndrome (ASS) is known as a severe type of teratozoospermia, defined as semen composed of mostly headless spermatozoa that affect male fertility. In this regard, this systematic review aimed to discuss gene variants associated with acephalic spermatozoa phenotype as well as the clinical outcomes of intracytoplasmic sperm injection (ICSI) treatment for the acephalic spermatozoa-associated male infertility.MethodsA systematic search was performed on PubMed, Embase, Scopus, and Ovid databases until May 17, 2020. This systematic scoping review was reported in terms of the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) statement.ResultsTwenty articles were included in this systematic review. Whole-exome and Sanger sequencing have helped in the identification of variants in SUN5, PMFBP1, BRDT, TSGA10, DNAH6, HOOK1, and CEP112 genes as possible causes of this phenotype in humans. The results of the ICSI are conflicting due to both positive and negative reports of ICSI outcomes.ConclusionASS has a genetic origin, and several genetic alterations related to the pathogenesis of this anomaly have been recently identified. Notably, only SUN5 and PMFBP1 mutations are well-known to be implicated in ASS. Accordingly, more functional studies are needed to confirm the pathogenicity of other variants. ICSI could provide a promising treatment for acephalic spermatozoa-associated male infertility. Besides the importance of sperm head-tail junction integrity, some other factors, whether within the sperm cell or female factors, may be involved in the ICSI outcome.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10815-020-02008-w.