Genetic analyses of Chinese patients with digenic oculocutaneous albinism

Background Oculócutaneous albinism (OCA) is a heterogeneous and autosomal recessive disorder in all populations worldwide.The mutational spectra of OCA are population-specific.Some OCA patients carry m...     

多发性内分泌腺瘤综合征家系MEN1基因突变及功能分析

目的对一例多发性内分泌腺瘤综合征（multiple endocrine neoplasia type1,MEN1）家系进行基因突变检测及功能分析,以探讨MEN1发病的分子机制。方法对家系两名确诊患者及其他6名成员进行相关生化检查,留取外周血液标本,提取基因组DNA,采用PCR方法扩增MEN1基因所有编码序列,包括9个外显子及外显子／内含子边界,并进行直接测序。免疫组织化学法对2名患者肿瘤组织menin蛋白进行检测。结果2名患者MEN1基因第三外显子存在插入突变C．433-434ins CTTC,可导致开放阅读框移位并提前出现终止密码子。家系其他成员未发现MEN1基因突变。患者肿瘤组织中无menin蛋白表达。结论一种新型的MEN1基因突变形式被定位,这将有利于MEN1疾病的早期分子诊断。     

眼皮肤白化病Ⅱ型产前基因诊断研究及二种P基因新突变

目的对1例眼皮肤白化病（OCA）患儿进行基于DNA的分型诊断,并在此基础上进行OCA产前基因诊断。方法应用PCR技术、DNA序列测定技术和变性高效液相层析（DHPLC）技术,分析患儿及其父母的OCA相关基因,确定患儿的分型诊断和基因型后,于其母孕20周时取羊水,以DNA序列测定技术进行OCA产前基因诊断。结果先证者’rYR基因未见突变,1对P基因分别存在N476D和Y827H突变。群体中100名表型正常者中未见此2种突变等位基因。胎儿获得了母源性N476D突变,未获得父源性Y827H突变,推测胎儿为表型正常的致病基因携带者。胎儿出生后表型正常,与产前基因诊断结果相符。结论成功开展了1例OCA2产前基因诊断并发现2种致病性P基因新突变N476D和Y827H,对今后开展该病的基础研究和预防与优生工作具有重要意义。     

家族性慢性良性天疱疮一家系致病基因新突变的发现

目的对家族性慢性良性天疱疮一家系的ATP2C1基因突变进行检测。方法采用聚合酶链反应扩增该家系患者和健康对照个体ATP2C1基因的全部外显子,直接测序法进行DNA测序,100例无亲缘关系的正常人作为对照。结果该家系患者ATP2C1基因内含子3的末端235-2碱基发生了1个腺嘌呤（A）→鸟嘌呤（G）的杂合性剪接位点突变。家系中健康对照个体及无亲缘关系的正常对照均未发现该突变。结论该剪接位点突变可影响基因转录和翻译产物,是ATP2C1基因新的特异性突变。     

Goldenhar综合征家系的eya1基因突变检测

目的 探讨eya1基因在Goldenhar综合征家系中的作用.方法 收集1个Goldenhar综合征家系6例成员(患者4例,疑似病人2例)的血样,抽提基因组DNA,然后对eya1基因编码蛋白质的外显子3～18进行PCR扩增,测序分析PCR产物.结果 家系中患者和表型正常者有3个已知SNP改变.结论 排除eya1基因在该Goldenhar综合征家系中的作用,说明有新的致病基因有待发现.     

一例Ⅰ型成骨不全家系的基因定位及突变检测

目的对国内1例成骨不全(OI)家系进行基因突变及突变效应分析,为研究中国人群的成骨不全基因突变特点提供线索。方法对成骨不全Ⅰ型胶原基因COL1A1和COL1A2所在的17号染色体和7号染色体分别进行连锁分析,对致病基因做初步判断,然后用聚合酶链反应扩增致病基因外显子,并测序检出基因突变。结果该家系为COL1A1基因突变,所有患者在该基因的第8个内含子剪切受体位点处为AG→GG(IVS8-2A>G)突变。结论对比COL1A1基因突变数据库,该突变为一新发现突变。     

1例Angelman综合征合并眼皮肤白化病2型患者的临床和遗传学分析及文献回顾

总结1例Angelman综合征(Angelman syndrome, AS)合并眼皮肤白化病2型(oculocutaneous albinism type 2, OCA2)患儿的临床诊疗过程及遗传学检测结果和特点,并以“Angelman综合征”“眼皮肤白化病2型”“Angelman syndrome”“P gene”“Oculocutaneous albinism type 2”为关键词分别在CNKI、万方数据库及PubMed数据库(自建库至2019年12月)中检索,对国内外报道的AS合并OCA2病例进行汇总分析。本例患儿女,1岁,出生后即发现全身白,毛发色黄,眼球震颤,2个月会竖头,7个月会翻身,测头围42 cm,不能独坐,不会说话。家系全外显子组基因测序显示,患儿携带P基因c.168del(p.Gln58ArgfsTer44)纯合突变,经验证其父亲为杂合型,母亲为野生型。拷贝数变异检测提示,患儿母源染色体15q11.2-13.1区域缺失(P基因位于此区域内)。截至2019年12月,3个数据库中共检索到4篇相关文献,共报道了4例AS合并OCA2患儿,与本例一起进行汇总分析。AS合并O...     

遗传性对称性色素异常症家系中ADAR1基因的遗传分析

目的研究一个遗传性对称性色素异常症家系的致病基因。方法采用聚合酶链反应(PCR)后酶切测序的方法鉴定ADAR1基因是否存在变异。结果在先证者及其2个患病的儿子中同时检测到了ADAR1基因在编码区发现变异C.1105insA杂合改变,导致其编码的蛋白提前终止T369fsX374。结论 ADAR基因T369fsX变异导致了遗传性对称性色素异常症的发生。     

NIDDM患者胰岛素受体底物-1基因突变研究

目的：探讨胰岛素受体底物-1(IRS-1)基因Gly971Arg突变与非胰岛素依赖性糖尿病(NIDDM)的相关性。方法：采用多聚酶链式反应-限制性片段长度多态性(PCR-RFLP)分析方法，对60例NIDDM患者和30例正常个体IRS-1基因Gly971Arg突变进行筛查。结果：60例NIDDM患者中检测出2例Gly971Arg突变者，30例正常人中没有发现突变者。结论：IRS-1基因Gly971Arg突变在NIDDM患者中出现频率较正常人略高，Gly971Arg突变对IRS-1活性的影响及其在NIDDM发病中的作用有待进一步研究。     

一个佩梅病大家系蛋白脂蛋白1基因突变分析

目的分析并确定佩梅病(PMD)一大家系蛋白脂蛋白1(PLP1)基因突变及遗传特征。方法收集先证者及其家系成员临床资料,采用多重连接依赖的探针扩增(MLPA)方法进行PLP1基因重复突变检测、DNA直接测序进行PLP1基因点突变检测,分析基因型与表型的关系。结果本家系先证者(Ⅴ∶4)符合临床诊断PMD。PLP1基因检测结果发现先证者(Ⅴ∶4)存在第2外显子c.96C>G(p.F32L)的半合子改变,先证者之母(Ⅳ∶16)、外祖母(Ⅲ∶20)与曾外祖母(Ⅱ∶7)存在与先证者相同的c.96C>G(p.F32L)杂合改变,为表型正常的携带者。结论本家系中先证者为PLP1基因c.96C>G(p.F32L)半合子突变致病,明确了本家系PLP1基因突变与遗传特征,为准确的遗传咨询和进一步的产前诊断打下了基础。     

A novel mutation of the KIT gene in a Chinese family with piebaldism

Background Human piebaldism is a rare autosomal dominant condition characterized by congenital white forelock and depigmented patches of skin,typically on the forehead,anterior trunk and extremities.Mutations in the KIT gene have been proposed to be responsible for the underlying changes in this disorder.The aim of this study was to identify gene mutation in a Chinese family with piebaldism.Methods A Chinese family with piebaldism presenting with white forelock and large depigmented skin macules on the abdomen,arms and legs was collected.DNA was isolated from peripheral blood of the family members.The encoding exons with flanking intron regions of the KIT gene were analyzed by polymerase chain reactions (PCR) and direct DNA sequencing.Besides,DNA extracted from 100 ethnically matched population individuals was as controls.Results A heterozygous missense mutation c.2590T＞C was identified in the patients of the family.This mutation converted a serine residue to proline (p.Ser864Pro).The mutation was not found in their unaffected family members or normal controis.Conclusion A novel missense mutation c.2590 T＞C was found and it might play a significant role in the piebaldism phenotype in the family.     

Dowling-Meara型单纯性大疱性表皮松解症一家系角蛋白基因突变研究

目的：研究一家族性Dowling—Meara型单纯性大疱性表皮松解症(EBS)中的遗传基础，分析患者的基因突变及确定EBS的亚型。方法：应用外周血提取DNA、PCR扩增、基因序列分析的方法检测患病家族者的K5和K14的所有外显子区。结果：检测K5基因的所有外显子，未发现突变位点；检测了K14基因的所有外显子，在第一外显子区发现了R125C的突变。两例患者(母亲和女儿)具有相同的突变，而未患病的父亲及正常对照则无此突变。结论：该EBS-DM家系中存在K14基因R125C的突变，角蛋白基因突变的检测是区分EBS-DM患者表型和明确诊断的有效的方法。     

A novel mutation, Y255X, of the ARSB gene in a Chinese family with mucopolysaccharidosis type Ⅵ

Mucopolysaccharidoses (MPS) are lysosomal storage diseases with defectivedegradation of glycosaminoglycans. Mucopolysaccharidosis type Ⅳ( MPS Ⅳ )or Maroteaux-Lamy syndrome is caused by defective arylsulfatase B in the lysosomes ( ARSB; Nacetylgalactosamine-4-sulfatase, EC 3.1.6. 12 ) . The clinical manifestations of MPS VI include coarse facial features, growth retardation, short stature, skeletal malformations, hepatosplenomegaly, corneal clouding,and cervical myelopathy. Heart failure is the usual cause of death in the second or third decade of life. Despite all the physical disabilities, the intellect of MPS Ⅳ patients is preserved.     

进行性骨化性纤维增殖不良症临床及ACVR1基因c.774G>C突变分析

目的:研究1例具有非典型临床特征的进行性骨化性纤维增殖不良症(fibrodysplasia ossificans progressiva,FOP)患者,并对其致病基因人活化蛋白/促激蛋白A受体1 (activin A type 1 receptor,ACVR1)进行突变分析?方法:根据患者大踇趾轻微畸形和进行性异位骨化等临床表现,结合骨骼系统放射线检查?骨ECT和相关血液生化检查进行临床诊断?采集患者?患者父母和60位正常人外周血,提取基因组DNA,对ACVR1基因全部外显子进行聚合酶链反应(polymerase chain reaction,PCR)扩增和序列分析;对突变后的蛋白质结构进行分子模拟以便评估其突变后的功能改变?结果:患者具有非典型的临床表现:先天性大踇趾轻微畸形和进行性非经典顺序的异位骨化,其父母无FOP相关临床表现?患者的ACVR1第5外显子存在c.774 G>C (R258S)杂合突变,而其父母和正常对照组均无此杂合突变?此外,患者和所有正常人都存在c.690 G>A(E230E),此为无意义突变?三维蛋白质分子模拟发现R258与高度保守的甘氨酸-丝氨酸(glycine-serine,GS)活化区邻近,该突变可能导致ACVR1与ACVR1的抑制蛋白FK506结合蛋白12(FK506 binding protein 12,FKBP12)结合的亲和力降低,进而对ACVR1抑制作用降低?结论:典型FOP均在ACVR1之GS区发生突变,而本例FOP在ACVR1激酶区发生突变,这可能是该患者在临床表现呈非典型的原因?该结果有助于我们更好地去理解FOP表型和基因型之间的关系?     

应用实时荧光定量PCR技术检测常染色体 隐性遗传性早发型帕金森综合征的 DJ 1基因外显子重排突变

目的：建立应用实时荧光定量PCR技术（real time polymerase chain reaction,real time PCR）检测DJ 1基因外显子重排突变的技术平台,并应用该技术对常染色体隐性遗传性早发型帕金森综合征（autosomal recessive early onset Parkinsonism, AREP）DJ 1基因进行外显子重排突变分析。方法：应用实时荧光定量PCR分析方法,对22个AREP家系先证者和30个正常对照的DJ 1基因进行外显子重排突变分析。结果：本研究中获得了扩增效率和特异性均满意的DJ 1基因各编码外显子实时荧光定量PCR反应条件及各外显子引物;本组AREP患者未发现DJ 1基因的外显子重排突变。结论：建立了应用实时荧光定量PCR技术进行DJ 1基因外显子重排突变检测的技术平台;中国人群AREP患者DJ 1基因外显子重排突变可能罕见。     

Gene mutation in patients with primary open-angle glaucoma in a pedigree in China

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胰岛素受体基因第17外显子突变与2型糖尿病相关性研究

目的：研究胰岛素受体（Insulin receptor,INS-R)与2型糖尿病的相关性。方法：利用PCR－SSCP法对42例2型糖尿病患者及30例健康对照者INS－R基因第17外显子进行了研究。结果：在被检测的42例2型糖尿病患者中，5例检出异常带型（11.9%)，健康对照者未检出异常带型。结论：INS－R基因第17外显子突变可能与2型糖尿病具有相关性。     

A novel missense mutation of the ubiquitin protein ligase E3A gene in a patient with Angelman syndrome

Background  Angelman syndrome (AS) is a neurogenetic disorder caused by an expression defect of the maternally inherited copy of ubiquitin protein ligase E3A (UBE3A) gene from chromosome 15. Although the most common genetic defects include maternal deletions of chromosome 15q11-13, paternal uniparental disomy and imprinting defect, mutations in the UBE3A gene have been identified in approximately 10% of AS patients.

Methods  A Chinese girl of 28 months presented clinical manifestation of AS. Genetic diagnosis and molecular genetic defects were studied by methylation-specific PCR (MS-PCR) and linkage analysis by short tandem repeat (STR). We further performed sequence analysis of all the coding exons and flanking sequences of the UBE3A gene. The novel mutation screening was also performed in 100 unrelated healthy individuals to exclude the possibility of identifying a polymorphism variation.

Results  The MS-PCR analysis of the patient showed biparental inheritance of chromosome 15 with a normal methylation pattern in the 15q11-q13 region. And STR analysis revealed that the patient also inherited biparental alleles for six microsatellites. A novel mutation, cDNA1199 C>A (p.P400H), in exon 9 of the maternal UBE3A gene, was identified in the patient. Meanwhile, the mutation was observed in the patient’s mother who had a normal phenotype.

Conclusions  It is necessary to perform the UBE3A gene mutation analysis in non-deletion/non-UPD/non-ID patients with AS. The clinical picture of the patient is concordant with that observed in previously reported AS patients with UBE3A mutation.

     

A novel SMPD1 mutation in two Chinese sibling patients with type B Niemann-Pick disease

Type B Niemann-Pick disease is an autosomal recessive sphingolipidosis due to mutations in the sphingomyelin phosphodiesterase 1 gene (SMPD1). Here we present molecular findings for two sibling patients. One mutation V36A due to c.107T>C in exon 1 is a single nucleotide polymorphism and the other N522S due to c.1565 A>G in exon 6 is a novel missense mutation. This non-fatal missense mutation leads to –20% residual lysosomal acid sphingomyelinase activity in vitro and only results in hepatosplenomegaly without neurologic involvement.