X连锁隐性遗传无汗/少汗型外胚叶发育不全家系表型和基因型分析

目的:探讨X连锁隐性遗传无汗/少汗型外胚叶发育不全(XLHED)家系的遗传方式和表型特点,并对家系基因型进行分析。方法:采用临床检查和家系调查的方法,对通过先证者法收集的XLHED家系进行遗传方式和临床表现分析。利用直接测序法对家系EDA基因开放阅读框内外显子编码区及外显子-内含子接头区核苷酸进行序列分析。结果:收集到的家系为X连锁隐性遗传,男性患者临床表现典型,女性携带者有轻度临床表现或无症状,家系内表现度差异小。家系患者EDA基因第491位核苷酸由腺嘌呤颠变为胞嘧啶(c.491A>C)。结论:本研究收集家系的患者临床症状明显,为典型的XLHED家系。家系致病突变为一已知突变(E164A)。     

无汗/少汗型外胚叶发育不全家系致病基因的筛查

目的:探讨无汗/少汗型外胚叶发育不全(HED)家系的遗传方式及表型特点,并对家系致病基因进行筛查。方法:采用临床检查和家系调查的方法,对通过先证者法收集的HED家系进行遗传方式和临床表现分析。利用直接测序法对EDA、EDAR和EDARADD基因开放阅读框内外显子编码区及外显子-内含子接头区核苷酸序列进行分析。结果:收集到的家系为典型的无汗/少汗型外胚叶发育不全家系,先证者临床表现典型,毛发发育不良,头发、眉毛、睫毛稀疏;汗腺发育不良,无汗/少汗,体温随季节变化有明显改变;缺失多颗恒牙,并有乳牙滞留。家系内其他成员无明显异常表现。对EDA、EDAR和EDARADD基因开放阅读框的测序分析未找到致病突变。结论:本研究收集家系的患者临床症状明显,排除目前已知致病基因突变。     

外胚叶发育不全一家系的基因型分析

目的:分析外胚叶发育不全家系的表型特点和遗传特征,并对家系基因型进行分析。方法:收集1个外胚叶发育不全家系,采用临床检查和家系调查的方法,调查并记录先证者及家系成员的病史和体格检查资料。对家系成员EDAR基因开放阅读框内外显子编码区及外显子-内含子接头区核苷酸序列进行分析。结果:收集到的家系为常染色体显性遗传,患者临床表现典型,家系内表现度差异小。家系成员EDAR基因开放阅读框内未检测到基因突变。结论:本研究收集的外胚叶发育不全家系临床症状明显,致病基因排除EDAR基因。     

遗传异质性是无汗型外胚叶发育不全的重要特点

目的:对收集的1个湖北无汗型外胚叶发育不全(HED)家系进行遗传特点分析,并对HED已知致病基因EDA和EDAR进行突变检测。方法:通过先证者及现场家系调查收集HED家系。对EDA和EDAR开放阅读框内每个外显子编码区及外显子-内含子接头区设计引物,经聚合酶链式反应扩增并纯化后直接测序。结果:收集的HED家系遗传方式不能确定,临床表现典型。EDA和EDAR开放阅读框内的编码序列,仅检测到2个已知多态,未发现突变位点。结论:HED具有明显的遗传异质性,除EDA和EDAR外,还可能存在其他的致病基因。     

3个中国无汗型外胚叶发育不全家系遗传及临床特点分析

目的：探讨中国无汗型外胚叶发育不全家系（HED）的遗传方式和临床表型特点。方法：采用临床检查和家系调查的方法,对通过先证者法收集的3个HED家系进行遗传方式和临床表现分析。结果：两个家系为X连锁隐性遗传,另一个家系遗传方式不能确定。男性患者临床表现典型,女性携带者有轻中度临床表现或无症状,家系间严重程度不一致,表现度差异大。结论：HED外显率高,表现度差异大,具有明显的遗传异质性。     

X连锁无汗性外胚叶发育不全家系ED1基因的突变检测

目的探讨国内X连锁无汗性外胚叶发育不全家系中ED1基因的突变情况，为该病的遗传咨询、产前诊断、确诊携带者提供依据。方法收集2个X连锁无汗性外胚叶发育不全家系及1个散发患者的外周血样本，盐析法提取基因组DNA，采用聚合酶链反应（polymerase chain reaction，PCR）和直接测序对ED1基因进行突变检测。结果家系一患者ED1基因第9外显子发生错义突变（1045G〉A），家系二和散发患者ED1基因第3外显子发生错义突变，分别为467G〉A和466C〉T。结论ED1基因的错义突变可导致X连锁无汗性外胚叶发育不全。这3个突变与国外学者的报道一致。     

一个范德伍德综合征家系的IRF6基因突变检测

目的:对收集的1个湖北Van der Woude综合征(VWS)家系进行临床和遗传特点分析,并进行IRF6基因的突变检测。方法:通过先证者及现场家系调查、临床检查和系谱分析收集VWS家系。在IRF6基因的外显子-内含子接头及9个外显子编码区分别设计引物,经聚合酶链式反应扩增并纯化后直接测序。结果:收集的VWS家系符合常染色体显性遗传特征,家系受累患者共3名(1名男性和2名女性),患者表现为典型的下唇瘘管或凹陷,且合并有唇腭裂和先天缺牙。患者表型在同一家系内有明显差异,且呈逐代加重趋势。在所有患者IRF6基因第412位密码子发现与表型一致的CGA>TGA(c.1234C>T)改变,经查证为一个已知的无义突变。结论:该VWS家系疾病表现度极不一致,是由IRF6基因的1个已知无义突变导致,IRF6是参与颌面部发育的重要基因。     

外胚层发育不全无汗综合征患者基因突变的检测

目的：检测外胚层发育不全无汗综合征患者的EDA基因的突变。方法：提取外胚层发育不全无汗综合征患者的基因组DNA，采用PCR方法扩增EDA基因的第5、9外显子，直接将PCR产物送测序。结果：确证该患者是X染色体隐性遗传的外胚层发育不全无汗综合征，患者EDA基因的第5外显子存在突变位点：918位碱基C突变为A，致使226位线氨酸变为终止码，结论：该患者是X染色隐性遗传的外胚层发育不全无汗综合征，其EDA基因5外显子存在突变。     

少汗型外胚叶发育不良中EDA基因新突变位点的鉴定

目的 揭示少汗型外胚叶发育不良（hypohidrotic ectodermal dysplasia,HED）一种新的外异蛋白A（ectodysplasin A,EDA）基因突变。方法 抽取患者外周血,提取基因组DNA,运用全外显子测序方法对患者进行基因测序,使用一代Sanger测序验证突变位点。构建EDA1（ectodysplasin A1）野生型及突变型表达质粒,通过蛋白免疫印迹法检测EDA1突变型蛋白的表达和分泌;通过双荧光素酶分析,检测EDA1突变型蛋白对下游NF-κB通路活性的影响。采用SPSS 20.0 软件包对数据进行t检验。结果 发现了1例未报道的EDA基因突变位点c.649_666del （p.Pro217_Pro222del）。与野生型EDA1相比,突变型EDA1蛋白能正常表达和分泌,但其对下游NF-κB的转录激活显著降低（P<0.05）。结论 本研究鉴定了1例新的EDA基因缺失突变,扩展了X连锁少汗型外胚叶发育不良的突变谱,有助于产前咨询、诊断和矫正。     

遗传性牙龈纤维瘤病致病基因的排除性定位

目的:对我国现有的2例家族遗传性牙龈纤维瘤病进行国外已证实的已知基因突变位点--SOS1基因21号外显子的排除性定位。方法:采用PCR—SSCP-银染的方法对2例遗传性牙龈纤维瘤病家系的致病基因进行排除性定位。结果:两家系中均未发现SOS1基因的缺失。5％的聚丙烯酰胺凝胶电泳结果表明两家系中无典型临床表现者电泳条带无明显的异常，而有典型临床表现者发现家系1有4例患者的电泳条带有明显位移，条带离加样孔较正常对照近，家系2有2例患者的电泳条带有明显位移，但条带离加样孔较正常对照远。结论：两家系无典型临床表现者无SOS1基因的突变，有典型临床表现者存在有SOS1基因21号外显子的突变，但是，是否所有有典型临床症状的患者其基因突变的位置及涉及的碱基片段都相同还需进一步研究。     

Missense mutation of EDA1 gene in Japanese family with X-linked anhidrotic ectodermal dysplasia

X-linked anhidrotic ectodermal dysplasia (XLHED) is characterized by hypoplasia or absence of hair, teeth and sweat glands. In this study, the authors investigated the ectodysplasin-A1 (EDA1) gene was investigated in a Japanese family in which male member, a child, fulfilled the diagnostic for XLHED. The only affected male fulfils the diagnostic criteria for this disorder. His parents were not consanguineous and both of them were healthy. With informed consent, genomic DNA was isolated from oral buccal epithelial cells from all members of the family. Polymerase chain reaction fragments containing nine exons of the EDA1 gene were amplified. Amplified fragments from both the patient and the parents were directly sequenced. The sequence from the patient revealed a missense mutation (G643A) in exon 5 of the EDA1 gene, which changes codon 215 from glycine to arginine. Heterozygosity was demonstrated in the mother. The present results indicate that amino acid substitution occurs, disrupting the transmembrane domain, and strongly suggest that this was the disease-causing mutation in this family.     

A point mutation of the ED1 gene in a Japanese family with X-linked hypohidrotic ectodermal dysplasia

X-linked hypohidrotic ectodermal dysplasia (EDA) is characterized by the hypoplasia or absence of hair, teeth and sweat glands. In this study, the authors investigated the ED1 gene in a Japanese family with X-linked hypohidrotic ectodermal dysplasia. The only affected male fulfils the diagnostic criteria for this disorder. His parents were not consanguineous and both of them were healthy. After informed consent, genomic DNA was isolated from the peripheral blood lymphocytes or oral buccal epithelial cells of all members of the family. A polymerase chain reaction fragment containing exon 9 of the ED1 gene was amplified using primers. The patient's amplified fragment, as well as those from his father, mother and sister, were directly sequenced. The sequence from the patient revealed a point mutation (G1149A) in exon 8 of the ED1 gene, which changes codon 291 from glycine to arginine. Heterozygosity was demonstrated in his mother and sister. This mutation has not been reported previously. The amino acid substitution is predicted to disrupt the transmembrane domain, which strongly implies that this is the disease-causing mutation in the family.     

Molecular analysis for genetic counselling in amelogenesis imperfecta

OBJECTIVE: To use molecular genetics to establish the mode of inheritance in a family with amelogenesis imperfecta. MATERIALS AND METHODS: The polymerase chain reaction was used to amplify exons of the amelogenin gene on the short arm of the X chromosome. RESULTS: A single base deletion mutation in exon 6 of the amelogenin gene was identified. This mutation was a single base deletion of a cytosine residue - 431delC - in codon 96 of exon 6, introducing a stop codon 30 codons downstream of the mutation in codon 126 of the exon. CONCLUSION: The firm establishment of an X-linked mode of inheritance affects the genetic counselling for this family.     

Problems of genetic model testing in early onset periodontitis

Familial aggregation of early onset or juvenile periodontitis (JP), a disorder that varies in expression and age of onset, has been recognized for some time. Autosomal recessive and X-linked inheritance patterns have been suggested, and one large pedigree has demonstrated autosomal dominant inheritance. The variability and age limitations in clinical phenotypic diagnosis present several problems to genetic analysis, because information on members of the youngest and older generations may be lost to the analysis. The purpose of the present study was to elucidate the genetic basis of JP by formal pedigree analysis and comparison of competing genetic models. Twenty-eight families were included, with general and specific autosomal models, and an X-linked model being compared. The autosomal recessive model provided the most parsimonious explanation of the data, and its likelihood was not significantly different from the more general model. Likelihoods for the sporadic (nongenetic) and X-linked models were considerably lower than the autosomal models. While comparison of genetic models suggests recessive inheritance of JP, the serious complications to pedigree analysis posed by limitations warns against acceptance of this conclusion, without more exhaustive evaluation of: (1) a more extensive collection of family data, (2) more complete investigation of the effects of age limitations on comparisons among competing models, and (3) elucidation of the importance of diagnosis and phenotype assignment of adults through past dental records.     

纤维粘连蛋白片段真核表达载体pcDNA3．1（＋）-EDA的构建

目的构建纤维粘连蛋白（fibronectin，FN）基因的EDA外显子的真核表达载体，以研究EDA对涎腺腺样囊性癌（slivary adenoid cystic carcinoma，SACC）生物学行为的影响。方法以RT-PCR技术从口腔鳞状细胞癌（oral squamous cell carcinoma）细胞株KB中扩增出外显子EDA，克隆人pcDNA3．1（＋）真核表达载体，用PCR和限制性内切酶酶切、DNA测序鉴定真核表达载体pcDNA3．1（＋）-EDA。结果PCR、酶切、DNA测序鉴定证明成功构建了pcDNA3．1（＋）-EDA真核表达载体，DNA测序显示重组质粒含有与EDA片段基因序列完全相等的基因。结论成功构建了纤维粘连蛋白（fibronectin，Fn）基因的EDA外显子的真核表达载体pcDNA3．1（＋）-EDA。