2例类孟买表型的分子机理研究

本研究探讨2例类孟买血型表型的分子机理。先证者样本通过血清学方法鉴定为类孟买血型,采用PCR扩增先证者的FUT1和FUT2基因编码区序列,并对PCR产物进行直接测序分析。同时FUT1基因PCR产物经TOPOTA转染克隆到质粒上分离后,对其进行测序分析,以证实突变在染色体上的位置。结果表明：直接测序发现2例先证者FUT1基因第547-552位AG两碱基缺失杂合（CAGAGAG→CAGAG）和第658位C→T杂合。克隆后证实一条染色体上FUT1基因第547-552位中的两碱基AG缺失,可导致阅读框架发生移码,提前形成终止密码;另一条染色体上FUT1基因第658位C→T错义突变,导致第220位精氨酸（Arg）→半胱氨酸（Cys）。2例先证者FUT2基因均为357C→T同义突变。结论：2例先证者FUT1基因突变为不同染色体的复合性突变,均为h1h3。     

双碱基缺失型等位基因复合杂合导致的类孟买型个体1例

本研究探索1例类孟买型血型的分子机制,为稀有血型的筛选和鉴定提供理论基础。以血型血清学方法鉴定该个体红细胞的ABO和H表型,利用聚合酶链反应扩增类孟买表型个体的abo基因第6、7外显子和α1,2岩藻糖基转移酶基因(fut1)编码区,并对PCR产物直接测序分析。对纯化的fut1扩增产物进行TOPO克隆和测序,对2处变异位点进行单倍体序列分析。结果表明:血清学分析确认该个体为罕见的类孟买表型;直接测序发现先证者fut1基因第547位和880位附近存在碱基缺失或插入变异;TOPO克隆测序法证实,fut1基因1条单倍体存在第547-552位两碱基AG缺失,另1条单倍体存在880-882位两碱基TT缺失。这2种变异均导致移码突变,并提前形成终止密码。结论:在献血人群中发现1例罕见的类孟买表型,其分子机制为双碱基缺失型fut1等位基因复合杂合所致的α1,2岩藻糖基转移酶活性减弱。     

一例Bm~h类孟买血型的基因分析

目的鉴定1例ABO正反定型不符的血型,并分析其基因变异情况。方法使用标准血清学方法鉴定患者血型;对ABO基因的第6和第7外显子进行PCR扩增及测序;对FUT1基因的第4外显子和FUT2基因的第2外显子进行PCR扩增及测序。结果经血清学检测,此例ABO血型正定型为O型,反定型为B型;Lewis血型为Le(a-b+)。经基因测序分析,ABO基因型为B101/O01;FUT1基因型为h3/h3(c.658CT纯合突变);FUT2基因型为Se/Se。结论发现1例由FUT1基因c.658CT纯合突变导致的Bm~h类孟买血型。     

中国福建地区类孟买血型个体Fut1基因突变研究

本研究旨在探讨中国福建地区类孟买血型的分子机制。采用血清学方法鉴定研究对象为类孟买血型,采用PCR扩增研究对象的α1,2岩藻糖基转移酶(FUT1)基因编码区序列,并将PCR产物经TA后进行测序,分析fut1基因编码区序列,以证实类孟买血型的发生机制。结果表明,PCR扩增产物电泳分析证实成功扩增fut1基因编码区序列;克隆后测序分析发现本例先证者2条染色体上fut1基因均为第547-552位AG两碱基缺失(CAGAGAG→CAGAG),导致阅读框架发生移码,提前形成终止密码。结论:本例类孟买血型个体fut1基因为h1h1型纯合突变。     

FUT1 基因杂合或纯合突变致类孟买血型形成研究简

本研究旨在探讨类孟买血型表型形成的分子机制.采用血清学方法鉴定个体红细胞H抗原;采用高保真PCR扩增检测个体的α1,2岩藻糖基转移酶（FUT1）基因编码区序列,并进行测序、比对分析,以查明个体类孟买血型的发生机制.结果表明：凝胶电泳分析证实成功扩增FUT1基因编码区全长序列;克隆后测序、比对发现：个体1的1条染色体上FUT1基因为h1 （547-552delAG）,另1条染色体上为h4（35C＞ T）,为h1h4杂合子;个体2,3的2条染色体上FUT1基因均为h1 （547-552delAG）,为h1h1纯合子.结论：FUT1基因杂合或纯合突变均可致类孟买血型的发生.     

贵阳市1例稀有血型类孟买Bmh的检测分析

正人类ABO血型的A抗原和B抗原都是由前体物质H抗原转换而成的,绝大部分人群都有H抗原,但类孟买血型却部分或完全缺失,仅有的少量H抗原最终转换成A抗原或B抗原,从而在血清中产生相应的抗-A、抗-B和抗-H抗体。类孟买血型给实验室ABO定型和交叉配血带来困难,本例标本就是因医院输血科在ABO血型定型时出现正反不符,且用多袋     

贵州省黔西南布依族苗族自治州1例类孟买血型检测分析及输血策略

根据国际输血协会(ISBT)的定义,红细胞血型是指使用人类同种抗体检测的红细胞表面抗原,它们是由基因所决定的一种遗传性状[1].红细胞血型受ABO、FUT1、FUT2 和 FUT3 等 4 个基因的影响.FUT1 基因编码 H 转移酶,合成红细胞膜上和分泌液中的 H 物质,当 FUT1 基因发生突变时,酶活力减弱,表现为类孟买血型.类孟买血型在进行 ABO 血型鉴定时通常表现为正反定型不符,本文中的案例就是在对患者进行血型鉴定中被发现,经进一步的基因检测,证实为 B 型类孟买血型,现将研究结果报道如下.     

类孟买型Ahm分泌型的血型鉴定及输血

目的：血清学和分子生物学鉴定类孟买型Ahm分泌型,为患者准备手术用血。方法应用常规血清学方法检测患者红细胞抗原及血清中的抗体,吸收放散试验鉴定红细胞上弱表达的ABO抗原,测定唾液中的血型物质,进行分子生物学测序分析。结果患者血型为罕见的类孟买型Ahm分泌型,血清中有抗-H抗体。结论鉴定出罕见类孟买型,血清中含有抗-H,其FUT1基因为第547~552位AG两碱基缺失的纯合态,为最常见单体型。     

两例云南少数民族罕见FUT1基因位点突变致类孟买血型血清学与分子特征分析

类孟买血型属于H血型系统,H抗原缺乏表现型是指红细胞上完全或部分缺乏H抗原的稀有表现型.其中,H缺乏的非分泌型被称为孟买型,其个体红细胞和分泌液中均检测不到ABH抗原,而H缺乏和H部分缺乏的分泌型被称为类孟买型,红细胞表面缺乏ABH抗原,而在唾液等分泌液中却可以找到ABH血型物质.类孟买型在中国人群中鲜有报道,有资料表...     

类孟买血型鉴定1例

<正>我们对上海国妇婴保健院ABO定型困难而送检的孕妇血样进行了ABO血型鉴定,发现其为类孟买血型(Bhm),并对其做了进一步的血清学、基因测序及家系调查,现报道如下。1材料与方法1.1患者资料患者,女,32岁,汉族,籍贯上海,无输血史,无药物史。系上海国妇婴保健院妇产科患者,P1G0,怀孕18     

A Para-Bombay Blood Group Case Associated with a Novel FUT1 Mutation c.361G>A

BackgroundHere we report a case of para-Bombay phenotype due to a novel mutation FUT1 c.361G>A p.(Ala121Thr) and a nonfunctional allele FUT1*01N.13(c.881_882delTT) which showed a discrepancy in the routine ABO blood group typing.Materials and MethodsThe ABO phenotype and the Lewis blood group were typed with serological methods. The ABH antigens in saliva were determined by a hemagglutination inhibition test. The CDS region of ABO, FUT1and FUT2 were amplified with polymerase chain reaction and then directly sequenced. The novel mutation was confirmed by cloning and sequencing. Three-dimensional (3-D) structural analysis of the mutant and wild-type Fut1 were performed by the Chimera software.ResultsA, B and H antigens were not detected on the surface of red blood cells (RBCs) by the serological technique, and the B and H blood group substances were detected in the saliva, while the Lewis phenotype was Le(a–b+). Sequencing and cloning analysis showed the presence of a novel FUT1 mutation c.361G>A and a nonfunctional allele FUT1*01N.13(c.881_882delTT). The ABO genotype was ABO*B.01/ABO*O.01.01. The in silico analysis showed that the mutation p.(Ala121Thr) of FUT1did not change the 3-D structure of the whole enzyme but caused a certain amplitude of turnover in the loop region where Ala121 was located.ConclusionsA novel FUT1 allele (FUT1*c.361G>A) was identified in a Chinese individual with para-Bombay B phenotype. The FUT1c.361G>A mutation may significantly downregulate the expression of H antigens on RBCs by damaging the enzyme conformation.     

福建地区类孟买血型血清学特点及其基因突变分析

目的 研究福建地区类孟买血型血清学特点及其分子机制.方法 采用常规血清学方法对10例疑似类孟买血型样品进行红细胞表型鉴定,用吸收放散试验确证红细胞上弱表达的ABO抗原,PCR扩增ABO基因第6、7外显子及FUT1、FUT2基因编码区序列,并对PCR产物进行直接测序分析.结果 血清学和分子生物学方法证实10例样品皆为罕见...     

血清学和分子生物学鉴定Lewis血型抗体引起的输血反应

为了分析1例溶血性输血反应产生的原因，用谱细胞和Le（a—b-）表型细胞鉴定患者血清中的抗体，用抗Le^a和抗Le^b血型试剂鉴定患者红细胞表型，用PCR测序方法分析LE基因（FUT3基因）全编码区序列。结果表明：患者血清中有抗Le^a和抗Lc^b抗体，血型表型为Le（a—b-），LE基因型为无效等位基因纯合子（1e59，508）。结论：抗Le^b抗体可引起溶血性输血反应，患者FUT3基因突变导致Le（a—b-）表型。     

H抗原缺乏血型的表型频率及分子遗传学分析

目的了解福建省人群中H抗原缺乏血型的表型频率,研究其血清学和遗传学特征。方法用单克隆抗H试剂进行H抗原缺乏血型筛查;对经筛检出及其它来源的H抗原缺乏血型标本进行血清学分析及ABO血型初步鉴定;使用PCR-SSP进行ABO基因分型;对PCR扩增FUT1和FUT2基因的蛋白编码区产物进行测序,了解其基因型及核酸序列突变情况。结果从85390名献血者中检出10例H抗原缺乏血型,均为类孟买型(分泌型)。对14份类孟买型标本进行FUT1基因分析,检测出h1(nt547-552Δag)、h2(nt880-882Δtt)、h3(nt658c→t)和hnew-2(nt328g→a)4种隐性等位基因。这些个体的基因型分别为h1/h1(6例)、h1/h2(7例)和h3/hnew-2(1例),其中h1等位基因占67.85%,h2等位基因占25.00%。共检测12例类孟买型标本的FUT2基因,发现均存在纯合的nt357c→t突变,在FUT1基因型为h1/h2的个体中还检出nt716g→a突变,均为杂合子。未发现其它FUT2无效基因。血清学分析发现所有个体的不规则抗-A或抗-B在37℃中均无活性,而有7份标本血清中存在37℃具有活性的抗-H或抗-HI。结论福建省人群中类孟买型的表型频率估计约为1∶8 500。在福建省类孟买型个体中h1和h2等位基因具有一定的地域流行特征,存在h1-Se357和h2-Se357,716的单元型连锁遗传。     

Molecular analysis of secretor type α(1,2)-fucosyltransferase gene mutations in the Chinese and Thai populations

BACKGROUND: The human Lewis histo-blood group system belongs to a family of structurally related oligosaccharides. The mutations of fucosyltransferase genes alpha(1,2)-fucosyltransferase (FUT2 or Se) and alpha(1,3/1,4)-fucosyltransferase (FUT3 or Le), are responsible for the polymorphism of Lewis blood group phenotypes. However, a population study of the FUT2 mutation in Chinese and Thais has not yet been done, and there is some controversy about the phenotypes of Le(a+b+) and Le(a+b-). STUDY DESIGN AND METHODS: One hundred twentyfour Chinese and 70 Thais were phenotyped for Lea and Le(b). DNA samples were studied by polymerase chain reaction and then by a restriction enzyme digestion method to distinguish wild-type and six known mutations. Direct sequencing was done for controls and some uncertain cases. RESULTS: A new mutation, C302T mutation, was found in 2 of 136 chromosomes in the Thai population; none were discovered in Chinese. The frequencies of the normal and six mutant alleles among Chinese and Thais, respectively, were as follows: 134 (54.0%) of 248 and 58 (41.4%) of 140 were wild-type (Se); 0 of 248 and 2 of 140 (both 1.4%) had the G428A mutation; 120 (48.4%) of 248 and 75 (53.6%) of 140 had the A385T mutation; 2 (0.81%) of 248 and 0 of 140 had the C571T mutation; and 1 (0.4%) of 248 and 3 (2.2%) of 140 had the G849A mutation. Only 1 Chinese (0.4%) of 248 had the C628T mutation, and none had fusion gene mutation. CONCLUSION: The FUT2 genes encoding for the phenotypes Le(a+b+) and Le(a+b-) are the same. The function and character of the mutant enzyme may play an important role in the phenotype. The methods used in this study are clinically applicable in population studies of the FUT2 gene polymorphism to explore relationships among different ethnic groups and correlations between phenotype and genotype.