一个婴儿恶性石骨症家系的遗传学分析

目的 对一个婴儿恶性石骨症家系进行遗传学分析，明确遗传学病因，并对该家系中的1个高危胎儿进行产前诊断。方法 对先证者及其父母行二代测序查找可疑致病性基因变异，应用Sanger测序验证该变异，并明确同患病的先证者妹妹的基因型，以及该家系高危胎儿的基因型。结果 该家系先证者及其妹妹存在TCIRG1基因致病性复合杂合变异c.[1213G>A];[1555-2A>C]，其中c.1213G>A杂合变异遗传自先证者母亲，c.1555-2A>C杂合变异遗传自先证者父亲。产前诊断结果提示胎儿携带父源性c.1555-2A>C杂合变异，不携带母源性变异。结论 TCIRG1基因复合杂合变异c.[1213G>A];[1555-2A>C]可能是该家系婴儿恶性石骨症的致病原因。准确的遗传学分析为该家系进行遗传咨询和产前诊断提供了可靠依据。     

五个成骨不全家系COL1A1基因的变异分析

目的分析5个成骨不全家系的COL1A1基因致病变异位点,为家系遗传咨询及产前诊断提供依据。方法应用高通量测序方法对5个成骨不全家系的先证者进行225个骨病相关基因进行检测分析,所检岀的可疑变异经PCR扩增后进行Sanger测序,对5个家系的先证者及其家庭成员和100名正常个体进行验证,确定致病性变异后,对1个家系中的高危胎儿进行产前诊断。结果5个家系的先证者分别携带COL1A1基因c.3226G>A(p.Glyl076Ser)杂合错义变异、c.579delT(p.Glyl94Valfs*71)移码变异、c・2911_2912insAG(p.Gly971Glufs*138)插入变异、c.3037G>A(p.Glyl013Arg)杂合错义变异,以及c.642+5G>A杂合剪接变异;家系1胎儿产前诊断结果提示胎儿未携带与先证者相同的变异,与超声检查结果一致。5个家系的父母均未携带相应的变异,均为新发变异。100名正常个体均未检出上述变异。其中COL1A1基因c.3037G>A(p.Glyl013Arg),c.29U_2912insAG(p.Gly971Glufs*138)变异为未报道的新变异。结论COL1A1基因变异是5个成骨不全家系的致病病因。本研究的结果丰富了COL1A1基因的变异谱,为家系遗传咨询和产前诊断提供了依据。     

一个非综合征型耳聋家系的分子病因学分析

目的分析一非综合征型耳聋家系的分子病因,为患病家系遗传咨询和产前诊断提供依据。方法采用聚合酶链反应(polymerase chain reaction,PCR)和Sanger测序法对4名耳聋患者进行GJB2和SLC26A4基因编码区及侧翼序列测序。结果先证者GJB2基因序列测定为野生型,检出SLC26A4基因c.240delC和c.2168A>G复合杂合突变。先证者父亲检出SLC26A4基因c.240delC杂合突变,先证者母亲检出SLC26A4基因c.563T>C、c.1746delG和c.2168A>G三个杂合突变,先证者妹妹检出SLC26A4基因c.240delC、c.563T>C和c.1746delG三个杂合突变。其中,SLC26A4c.240delC为未见报道的新发框移突变,其余三个突变均为文献已报道的致病突变。结论该家系先证者、先证者母亲及先证者妹妹均为SLC26A4基因复合杂合突变导致的非综合征型耳聋,先证者父亲仅检出单杂合突变。明确基因突变有助于该家系进行遗传咨询和婚育指导,避免聋儿出生。     

遗传性耳聋家系的致病原因分析及产前诊断

目的 对3个先天性耳聋家系进行遗传性耳聋基因检测及突变类型分析,为再生育的家庭提供遗传咨询及产前诊断。方法 对在宁波市妇女儿童医院就诊的3例先天性耳聋患儿抽取静脉血,提取DNA。先应用目标基因捕获和高通量测序技术对先证者进行耳聋基因相关的全外显子和相邻内含子测序,利用生物信息学技术对测序数据进行分析,筛选相关变异基因并对其进行致病性分析。再应用Sanger测序法对先证者及其父母做基因突变位点验证。最后对第二胎需要进行产前诊断的孕妇采集羊水进行位点验证。结果 家系1先证者中检出肌球蛋白XVA(myosinXVA,MYO15A)基因c.2075C>A、c.4520G>A、c.6668C>T和c.10250＿10252del杂合突变。家系2先证者中检出MYO15A基因c.5964+3G>A和c.7395+6T>G复合杂合突变。家系3先证者中检出缝隙连接蛋白β2(gap junction protein beta 2,GJB2)基因c.299＿300delAT和c.109G>A复合杂合突变。产前诊断结果显示家系1和家系2胎儿的基因型均与先证者的不同,听力表型...     

六个成骨不全家系的临床表型分析及基因变异检测

目的分析6个成骨不全家系的临床表型并明确其致病变异,为遗传咨询及产前诊断提供依据。方法收集6个家系的临床资料以及外周血或引产组织样本,应用二代测序(next generation sequencing,NGS)技术对先证者的全部基因进行检测,用PCR反应扩增检出的变异位点,之后进行Sanger测序。在6个家系的所有成员以及100名健康对照中对检测到的变异位点进行验证。结果家系1的先证者及其女儿携带COL1A1基因c.1976G>C杂合变异,家系2~6的先证者分别携带COL1A2基因c.2224G>A、COL1A1基因c.2533G>A、COL1A2基因c.2845G>A、COL1A1基因c.2532_2540delCGGACCCGC以及COL1A2基因c.1847G>A杂合变异。先证者的双亲均未携带相应变异,在100名健康对照中均未检测到上述变异。结论6个成骨不全家系的致病原因可能均为COL1A1/2基因的变异。新发现的变异丰富了成骨不全症的表现型-基因型数据库,并为这些家系的遗传咨询及产前诊断提供了依据。     

七个鸟氨酸氨甲酰基转移酶缺陷症家系基因变异分析及产前诊断

目的对7个鸟氨酸氨甲酰基转移酶缺陷症(ornithine transcarbamylase deficiency,OTCD)家系进行OTC基因变异检测,明确其致病原因并为家系的遗传咨询和产前诊断提供依据。方法应用靶向高通量测序(next-generation sequencing,NGS)技术对7例经串联质谱筛查或临床诊断可疑OTCD的患儿或其母亲进行遗传代谢病相关基因panel检测,发现可疑致病变异位点后,应用PCR扩增和Sanger测序进行变异验证分析。在患儿母亲再次妊娠时抽取绒毛或羊水细胞进行相应基因变异检测,用于产前诊断。结果7个家系中共检测到7种OTC基因变异,分别为c.583G>A(p.Glyl95Arg).c.6260 T(p.Ala209Val)、c.6740 T(p.Pro225Leu)、c.482A>G(p.Asnl61Ser)、IVS1-2A>G、c.116G>T(p.Gly39Val).c.898delT(p.300Phefs*22),其中IVSl-2A>G、c・116G>T(p.Gly39Val)和c.898delT(p.300Phefs*22)为未报道过的新变异。产前诊断家系中3例胎儿基因测序均发现携带OTC基因变异半合子,性别为男性,孕妇选择终止妊娠,胎儿流产组织基因变异分析结果与产前诊断一致;另1例胎儿为OTC基因杂合变异,性别为女性,出生后新生儿筛查结果阴性,随访12个月,生长发育未见异常。结论OTC基因变异为7个OTCD家系的致病原因,致病变异的检出为家系的遗传咨询和产前诊断提供了依据。     

一个 FOXI1基因复合杂合变异所致常染色体隐性耳聋4型伴前庭导水管扩大家系的基因诊断

目的探究一个罕见的前庭导水管扩大耳聋家系的致病基因变异类型, 明确可能的遗传学病因。方法应用全外显子组测序对一个听力障碍合并前庭导水管扩大的耳聋家系中的先证者进行基因检测, 用Sanger测序法对侯选变异进行验证, 并对先证者父母和弟弟进行检测。结果先证者基因组DNA中检测到2个与常染色体隐性耳聋4型伴前庭导水管扩大相关的FOXI1基因c.748dupG(p.Asp250Glyfs*30Asn)(致病, PVS1+PM2+PP4, 尚未见报道)杂合变异和c.879C>A(p.Ser293Arg)(疑似致病, PM2+PM3+PP1+PP4, 首次报道)杂合变异, 先证者父母听力正常, 分别为FOXI1基因c.748dupG杂合变异和c.879C>A杂合变异携带者。先证者弟弟听力正常, 携带FOXI1基因c.748dupG杂合变异。结论该家系为一个罕见的FOXI1基因复合杂合变异导致的常染色体隐性耳聋4型伴前庭导水管扩大耳聋家系, FOXI1基因c.748dupG和c.879C>A为新发现的变异, 是该家系耳聋发生的遗传学病因, 可以根据上述发现对家系进行遗传咨询和再发...     

一例二氢嘧啶酶缺陷症患儿的基因变异分析

目的对1例二氢嘧啶酶缺陷症患儿进行基因变异分析, 探讨其可能的分子遗传学病因。方法收集先证者及其家系成员外周血, 提取基因组DNA, 应用全外显子测序技术确定致病基因, 并用Sanger测序进行验证。结果测序结果显示患儿的DPYS基因存在第5外显子c.905G>A(p.Arg302Gln)纯合变异, 父母均为c.905G>A(p.Arg302Gln)杂合变异携带者。结论 DPYS基因c.905G>A纯合变异可能是该家系患儿的致病原因, 致病变异的检出为家系的遗传咨询和产前诊断提供了依据。     

三个 FKRP基因变异所致的肢带型肌营养不良2I型家系的临床表现及遗传学分析

目的分析3个FKRP基因变异导致肢带型肌营养不良2I型(limb girdle muscular dystrophy type 2I, LGMD2I)家系的临床表型和基因变异特点。方法收集3例先证者的临床资料并对其进行肌肉活检。提取先证者及其家系成员的外周血样, 采用全外显子组测序技术筛查先证者致病基因, 确定可疑致病变异后对家系成员采用Sanger测序进行验证。结果先证者1和先证者2均存在双下肢无力的症状, 其中先证者1行走能力丧失伴有肺通气功能障碍。先证者3存在下肢疼痛和剧烈运动后心悸、憋喘症状。3例先证者肌肉病理可见肌营养不良表现和α-抗肌萎缩相关糖蛋白分子的表达量降低。基因测序结果显示先证者1FKRP基因存在c.545A>G(p.Y182C)和c.1391A>T(p.N464I)复合杂合变异, 先证者2存在c.545A>G(p.Y182C)和c.941C>T(p.T314M)复合杂合变异, 先证者3存在c.545A>G(p.Y182C)和c.161G>A(p.R54Q)复合杂合变异。C.545A>G(p.Y182C)、c.1391A&g...     

常染色体显性多囊肾病家系的 PDK1基因变异检测与产前诊断

目的探讨8个多囊肾病家系的致病变异位点, 为常染色体显性多囊肾病(autosomal dominant polycystic kidney disease, ADPKD)的遗传咨询和产前诊断提供理论依据。方法应用全外显子组测序和高通量测序技术检测8个独立家系中先证者的PKD1、PKD2基因, 通过Sanger测序进行位点验证和家系分析, 结合多囊肾疾病数据库和蛋白变异预测软件进行生物信息学分析。结果检测出8个PDK1变异, 包括5个无义变异和3个错义变异。其中4个无义变异PDK1:c.7555C>T, c.7288C>T, c.4957C>T和c.11423G>A已报道为ADPKD的致病变异, 1个错义变异PDK1:c.2180T>G(p.Leu727Arg)报道为可能致病的变异;3个变异位点未见报道, c.6781G>T(p.Glu2261*), c.109T>G(p.Cys37Gly), c.8495A>G(p.Asn2832Ser), 其中无义变异PDK1 c.6781G>T(p.Glu2261*)为致病变异, 错义变异PDK...     

Analysis of DYSF gene mutations in two pedigrees affected with limb-girdle muscular dystrophy type 2BCSCD

Objective: To analyze mutations of DYSF gene in two pedigrees affected with limb-girdle muscular dystrophy 2B (LGMD-2B). Methods: Genomic DNA was extracted from peripheral blood samples of the two probands and unaffected family members. Variant sites were screened by next-generation sequencing using gene panel as well as Sanger sequencing. Results: Four pathogenic mutations of the DYSF gene were detected, which included a de novo mutation and three mutations with uncertain significance. In pedigree 1, the proband carried compound heterozygous mutations of c. 1667T>C (p. Leu556Pro) and c. 5567T>A (p. Vall856Glu), which were respectively inherited from her mother and father. Proband of pedigree 2 carried compound heterozygous mutations of c. 4853A>G (p. Tyrl618Cys) and c. 4876G> A (p. Vall612Ile), among which c. 4876G> A (p. Vall626Ile) was also found in his father and grandfather, while c. 4853A>G (p. Tyrl618Cys) was detected in his mother and grandmother. Conclusion: The two compound heterozygous mutations of the DYSF gene probably underlie the LGMD2B in the two pedigrees. Next generation sequencing has conferred great advantage for gene diagnosis of hereditary myopathy. © 2018 MeDitorial Ltd. All rights reserved.     

Novel sequence variants in the TMC1 gene in Pakistani families with autosomal recessive hearing impairment

Though many hearing impairment genes have been identified, only a few of these genes have been screened in population studies. For this study, 168 Pakistani families with autosomal recessive hearing impairment not due to mutations in the GJB2 (Cx26) gene underwent a genome scan. Two-point and multipoint parametric linkage analyses were carried out. Twelve families had two-point or multipoint LOD scores of 1.4 or greater within the transmembrane cochlear expressed gene 1 (TMC1) region and were subjected to further screening with direct DNA sequencing. Five novel putatively functional non-synonymous sequence variants, c.830A>G (p.Y277C), c.1114G>A (p.V372M), c.1334G>A (p.R445H), c.2004T>G (p.S668R), and c.2035G>A (p.E679K), were found to segregate within seven families, but were not observed in 234 Pakistani control chromosomes. The variants c.830A>G (p.Y277C), c.1114G>A (p.V372M), and c.1334G>A (p.R445H) occurred at highly conserved regions and were predicted to lie within hydrophobic transmembrane domains, while non-synonymous variants c.2004T>G (p.S668R) and c.2035G>A (p.E679K) occurred in extracellular regions that were not highly conserved. There is evidence that the c.2004T>G (p.S668R) variant may have occurred at a phosphorylation site. One family has the known splice site mutation c.536 -8T>A. The prevalence of non-syndromic hearing impairment due to TMC1 in this Pakistani population is 4.4% (95%CI: 1.9, 8.6%). The TMC1 protein might have an important function in K(+) channels of inner hair cells, which would be consistent with the hypothetical structure of protein domains in which sequence variants were identified.     

五个Dysferlinopathy家系的 DYSF基因变异分析

目的:对5个Dysferlinopathy家系进行 DYSF基因变异分析,明确其致病原因。 方法:应用高通量测序技术进行检测,确定可疑变异后应用Sanger测序进行变异位点验证,根据美国医学遗传学及基因组学学会(American College of Medical Genetics and Ge...     

Novel RS1 mutations associated with X-linked juvenile retinoschisis

To identify mutations in the retinoschisin (RS1) gene in families with X-linked retinoschisis (XLRS). Twenty families with XLRS were enrolled in this study. All six coding exons and adjacent intronic regions of RS1 were amplified by polymerase chain reaction (PCR). The nucleotide sequences of the amplicons were determined by Sanger sequencing. Ten hemizygous mutations in RS1 were detected in patients from 14 of the 20 families. Four of the ten mutations were novel, including c:176G>A (p:Cys59Tyr) in exon?3, c:531T>G (p:Tyr177X), c:607C>G (p:Pro203Ala) and c:668G>A (p:Cys223Tyr) in exon?6. These four novel mutations were not present in 176 normal individuals. The remaining six were recurrent mutations, including c:214G>A (p:Glu72Lys), c:304C>T (p:Arg102Trp), c:436G>A (p:Glu146Lys), c:544C>T (p:Arg182Cys), c:599G>A (p:Arg200His) and c:644A>T (p:Glu215Val). Our study expanded the mutation spectrum of RS1 and enriches our understanding of the molecular basis of XLRS.     

16例Citrin蛋白缺陷所致的婴儿肝内胆汁淤积症的SLC25A13基因变异分析CSCD

目的探讨16例Citrin蛋白缺陷所致的婴儿肝内胆汁淤积症(neonatal intrahepatic cholestasis caused by citrin deficiency,NICCD)SLC25A13基因的变异特点。方法应用高通量测序法对目标基因的编码外显子和侧翼区域进行捕获,对变异位点进行Sanger测序验证和致病性分析。结果在16例NICCD患儿中,共发现致病变异15种,其中6种既往未见报道,包括IVS14-9A>G、c.1640G>A、c.762 T>A、c.736delG、c.1098delT、c.851G>A。结论通过高通量测序发现6种新变异,丰富了SLC25A13基因的变异谱,为患儿家系的遗传咨询和产前诊断提供了依据。     

FBN1新生突变引起的马凡综合征及其基因型-表型的关联研究

 目的: 本研究对2个不同马凡综合征(Marfan syndrome)的小家系进行致病基因FBN1的编码区和剪切位点突变检测,以寻找致病的突变,并初步探索马凡综合征基因型-表型的关联。方法: 通过临床检查、实验室检查及心脏超声检查确诊2个无血缘关系的家庭中原疑似为马凡综合征的3例患者。运用新一代测序对家系1的疑似患者行FBN1基因的全外显子组测序,并对检出的致病性遗传变异进行Sanger验证及在所有家系成员中验证;对于家系2的存活成员,本研究直接进行PCR扩增FBN1基因的所有编码区及剪切位点,对产物进行直接Sanger测序。另外在50个正常对照中对新发现的突变位点进行基于PCR产物的测序分析,以排除多态性;并对实验结果行生物信息学分析。结果: 所有存活的疑似患者均确诊为马凡综合征。在家系1中,我们检测到了一个FBN1基因数据库中尚未报道的新突变c.4685G>A(p.Cys1562Tyr),并且患者父母和同胞姐姐均未检测到此变异,故此突变为一个新生突变。该错义突变使第1562位上极性中性的含硫的半胱氨酸被极性中性的含羟苯基的酪氨酸所替代,影响了fibrillin-1蛋白一个TGF-β结合结构域,导致蛋白质的二级结构发生改变。家系2含父母及一对同卵双胎患者,其中一患者已去世。我们在存活患者检测到1个FBN1基因的已报道致病突变c.3706T>C(p.Cys1236Arg),该突变在患者父母中不存在,故也为新生突变。结论: 本文报道了一例FBN1基因的新突变及另一例由FBN1基因已知突变引起的马凡综合征,二者皆为新生突变,并在家系中进行了基因型-表型的比较,表明家系1的新突变可能与经典马凡综合征的表型相关,而家系2的已知突变确和新生儿重症马凡综合征表型相关。     

Identification of the bruton tyrosine kinase (BTK) gene mutations in 20 Australian families with X-linked agammaglobulinemia (XLA)

X-linked agammaglobulinemia (XLA) is an immunodeficiency caused by mutations in the Bruton tyrosine kinase (BTK) gene. Twenty Australian patients with an XLA phenotype, from 15 unrelated families, were found to have 14 mutations. Five of the mutations were previously described c.83G>A (p.R28H), c.862C>T (p.R288W), c.904G>A (p.R302G), c.1535T>C (p.L512P), c.700C>T (p.Q234X), while nine novel mutations were identified: four missense c.82C>A (p.R28S), c.494G>A (p.C165Y), c.464G>A (p.C155Y), c.1750G>A (p.G584E), one deletion c.142_144delAGAAGA (p.R48_G50del), and four splice site mutations c.241-2A>G, c.839+4A>G, c.1350-2A>G, c.1566+1G>A. Carrier analysis was performed in 10 mothers and 11 female relatives. The results of this study further support the notion that molecular genetic testing represents an important tool for definitive and early diagnosis of XLA and may allow accurate carrier status and prenatal diagnosis.     

Functional analysis of 13 GBA mutant alleles identified in Gaucher disease patients: Pathogenic changes and "modifier" polymorphisms

Gaucher disease, the most prevalent sphingolipidosis, is caused by the deficient activity of acid beta-glucosidase, mainly due to mutations in the GBA gene. Over 200 mutations have been identified worldwide, more than 25 of which were in Spanish patients. In order to demonstrate causality for Gaucher disease, some of them: c.662C>T (p.P182L), c.680A>G (p.N188S), c.886C>T (p.R257X), c.1054T>C (p.Y313H), c.1093G>A (p.E326K), c.1289C>T (p.P391L), c.1292A>T (p.N392I), c.1322T>C (p.I402T), and the double mutants [c.680A>G; c.1093G>A] ([p.N188S; p.E326K]) and [c.1448T>C; c.1093G>A] ([p.L444P; p.E326K]), were expressed in Sf9 cells using a baculovirus expression system. Other well-established Gaucher disease mutations, namely c.1226A>G (p.N370S), c.1342G>C (p.D409H), and c.1448T>C (p.L444P), were also expressed for comparison. The levels of residual acid beta-glucosidase activity of the mutant enzymes produced by the cDNAs carrying alleles c.662C>T (p.P182L), c.886C>T (p.R257X), c.1054T>C (p.Y313H), c.1289C>T (p.P391L), and c.1292A>T (p.N392I) were negligible. The c.1226A>G (p.N370S), c.1322T>C (p.I402T), c.1342G>C (p.D409H), c.1448T>C (p.L444P), and [c.1448T>C; c.1093G>A] ([p.L444P; p.E326K]) alleles produced enzymes with levels ranging from 6 to 14% of the wild-type. The three remaining alleles, c.680A>G (p.N188S), c.1093G>A (p.E326K), and [c.680A>G; c.1093G>A] ([p.N188S; p.E326K]), showed higher activity (66.6, 42.7, and 23.2%, respectively). Expression studies revealed that the c.1093G>A (p.E326K) change, which was never found alone in a Gaucher disease-causing allele, when found in a double mutant such as [c.680A>G; c.1093G>A] ([p.N188S; p.E326K]) and [c.1448T>C; c.1093G>A] ([p.L444P; p.E326K]), decreases activity compared to the activity found for the other mutation alone. These results suggest that c.1093G>A (p.E326K) should be considered a "modifier variant" rather than a neutral polymorphism, as previously considered. Mutation c.680A>G (p.N188S), which produces a mutant enzyme with the highest level of activity, is probably a very mild mutation or another "modifier variant."