发现1个新的无效RHD等位基因

目的鉴定1个疑似新的无效RHD等位基因。方法采用常规血清学方法检测1名孕妇的Rh血型抗原,间接抗球蛋白试验确认RhD抗原阴性,并用吸收放散试验排除D放散型(Del);先后分别采用商品化试剂盒、序列特异性引物PCR(SSP-PCR)技术以及DNA序列分析技术,分析该名个体的RHD基因。结果血清学试验为Rh-dCcEe,吸收放散试验阴性;基因型检测为杂合型RHD+/RHD-;商品化试剂盒和SSP-PCR结果都显示该个体携带的RHD阳性基因与正常Rh阳性表型的基因一致。对该标本编码区全长序列分析结果显示:第1外显子的第78位核苷酸缺失1个碱基"C",至第112位氨基酸时形成终止密码子。结论经GenBank检索发现该例为1个新的无效RHD等位基因,并完成注册RHD78delC(GenBank GQ477180)。     

一种新的RHD等位基因的分析鉴定

目的分析新RHD等位基因的基因结构。方法采用聚合酶链式反应(PCR)技术、序列特异性引物PCR(PCR-SSP)技术以及DNA序列分析技术,分析1例RhD阴性个体的RHD基因。结果序列特异性引物PCR(PCR-SSP)检测个例RHD基因的第3～7、9～10外显子,结果显示所检测的外显子均为阴性;检测RHD基因第2内含子(Din2)和Rh下游盒子区Box3,结果显示,Din2为阴性,Box3为阳性;检测RHCE基因,结果显示基因型为Ccee。应用3个PCR反应检测个例RHD基因的第10内含子(Din10),结果显示为阴性。个例的RHD基因编码区全长序列分析结果显示其第1、2外显子序列与正常RHD基因一致,其余外显子缺失。结论综合分析实验结果,个例为RHD抗原阴性,RHD基因阳性的个体,携带新的RHD-CE(2-10)融合等位基因。     

Anti-D in pregnant women with the RHD(IVS3+1G>A)-associated DEL phenotype

BACKGROUND: Pregnant women with the DEL phenotype appear to be D– by routine serology. Women with DEL phenotypes that show a partial D‐like epitope loss may develop anti‐D. It has been proposed that this alloantibody could have a deleterious effect with respect to hemolytic disease in the fetus and newborn. CASE REPORTS: Two pregnant women, one in Australia and one in Germany, were serotyped as D– and were sensitized to the D antigen. Noninvasive fetal RHD genotyping was performed to plan pregnancy management. RESULTS: In both cases the fetal RHD status could not be assigned due to the presence of a maternal DEL allele. This was suspected through detection of high RHD amplicon levels during quantitative polymerase chain reaction. For both cases extended molecular typing of the maternal genomic DNA revealed a RHD(IVS3+1G>A) allele. For case one, the D+ infant developed a mild hemolytic disease requiring phototherapy. In the second case a D– (or DEL) newborn was unaffected. CONCLUSION: Fetal genotyping from maternal plasma reveals RHD variants in pregnant women with anti‐D. Fetuses and newborns of sensitized pregnant women carrying the RHD(IVS3+1G>A) allele are at risk of hemolytic disease.     

RHD845A/1227A基因型个体家系调查分析

本研究对1例RHD845A/1227A基因型个体进行家系调查分析,并分析他们的遗传特性。通过盐水法和间接抗人球蛋白试验（IAT）检测RH（D）抗原,PCR—SSP法检测RHD1227A和RHD845A等位基因以及RHD合子型,基因测序方式分析RIHD基因编码区序列。研究结果表明：血清学检测发现1例RH（D）抗原盐水法检测阴性、IAT法检测阳性样本,经RHD基因编码序列分析发现,RHD第845位与第1227位均出现G／A碱基杂合现象,推测该个体基因型可能为RHD845A／1227A。家系调查显示,先证者父亲为RHD阴性,母亲为RHD阳性。PCR-SSP检测结果显示,父亲携带RHDl227A等位基因,基因型为RHD845A／RHD-;母亲携带RHD845A等位基因,基因型为RHD845A／RHD＋,证明先证者分别从父亲和母亲遗传RHD1227A和RHD845A等位基因,基因型为RHD845A／1227A。结论：经过家系调查分析发现了1例罕见的RHD845A／1227A基因型个体。根据家系调查证明,RHD845A和RHD1227A等位基因分别由遗传获得,而非由个体基因变异形成。     

D抗原阳性个体及无效等位基因携带者RHD基因数目测定

目的　测定Rh血型D抗原阳性个体的RHD基因数目。方法　采用聚合酶链式反应 限制性片段长度多态性 (PCR RFLP)技术 ,扩增 10名D阳性、5名弱D、2 5名Del表型和 12名携带无效等位基因的Rh阴性个体的RH基因座位下游盒子和融合盒子序列 ,产物经DNA限制性内切酶PstI消化后电泳 ,以 5份经血清学和序列分析基因分型方法确认的D阴性样本作为RHD-/RHD-纯合子对照 ,鉴定RHD+ /RHD+ 或RHD+ /RHD-基因型。结果　 10名D阳性个体均为RHD+ /RHD+ 纯合子、5份弱D样本及 12名携带无效等位基因的Rh阴性个体全部为RHD+ /RHD-杂合型。 2 5名Del表型个体中 9人为RHD+ /RHD+ 纯合型 (36 % ) ,其中 6人Rh表型为DCCee、3人为DCcee ;另 16名Del个体为RHD+ /RHD-杂合型 ,Rh表型均为DCcee。结论　D阳性个体RHD+ /RHD+ 纯合型多见 ,弱D型个体以RHD+ /RHD-杂合型为主 ,在Del表型个体存在高比率的RHD+ /RHD+ 纯合型 ;携带无效等位基因的个体多为RHD+ /RHD-杂合型     

A novel RHD allele caused by c.739 G> C mutation was identified in a Chinese individual

The blood sample of a pregnant Chinese woman of the north Han population was confirmed as D variation by serologic method, and subsequent detection of RHD Exons 1 through 10 by the polymerase chain reaction–sequence-specific primer test showed that all exons were present. To further clarify the molecular mechanism of this sample, we sequenced the RHD Exons 1 through 10 and found that it was a novel allele caused by c.739 G> C in Exon 5.     

Weak D and DEL alleles detected by routine SNaPshot genotyping: identification of four novel RHD alleles

BACKGROUND: Molecular RHD blood group typing is very efficient for managing donors and patients carrying any of the various molecular types of weak D and DEL. The purpose of the work was to develop a multiplex polymerase chain reaction (PCR) SNaPshot assay for simultaneous detection of weak D and DEL alleles that are prevalent in Europeans, Africans, and Asians. STUDY DESIGN AND METHODS: Preliminary profiling was carried out on single‐nucleotide polymorphisms (SNPs) associated with 13 prevalent RHD alleles, that is, weak D Types 1, 2, 3, 4.0, 4.0.1, 4.1, 4.2, 5, 11, 15, and 17; RHD(IVS3+1g>a); and RHD(K409K). Multiplex PCR was used to amplify six RHD regions encompassing 14 SNPs. Identification was obtained by incorporation of the complementary dye single base at the 3′‐end of each probe‐primer. A prospective analysis was then carried out on 152 blood samples from patients (n = 53) and donors (n = 88) with equivocal RhD serology and pregnant women (n = 11). RESULTS: After validation, our SNaPshot assay allowed direct genotyping of 82.9% of samples overall and 100% of samples harboring weak D Types 1, 2, 3, and 4.1 alleles. In the remaining 17.1% of samples overall, sequence investigation allowed accurate genotyping. In addition, four novel RHD alleles were identified, that is, RHD(S256P), RHD(L390L), RHD(F410V), and RHD(IVS4‐2a>g). CONCLUSION: The SNaPshot assay described herein is a helpful supplementary tool for resolving doubtful RhD serology. By allowing accurate identification of weak D and DEL alleles this assay should allow better management of the donors and the patients genotyped weak D Types 1, 2, 3, and 4.1 who can receive D+ blood units.     

Genotyping of RHD c.1227G>A allele by melting curve analysis

BackgroundDEL is the weakest known D-positive phenotype and is detectable only by adsorption and elution tests. RHD c.1227G>A is an important marker for DEL phenotype in East Asians. The aim of this study was to develop a method for RHD c.1227G>A genotyping by single-tube PCR with melting curve analysis.MethodsTwo GC-rich tails of different lengths were attached to the 5′-end of allele-specific primers for RHD 1227G and 1227A alleles, such that RHD c.1227G>A could be distinguished by the melting temperature. A total of 145 D-negative Chinese Han blood donors were genotyped for RHD c.1227G>A by melting curve analysis, conventional polymerase chain reaction with sequence-specific primers (PCR-SSP), and sequencing.ResultsIn 143 subjects (143/145, 98.6%), PCR-SSP and melting curve analysis produced consistent results with RHD exon 9 sequencings. Two samples were genotyped as RHD 1227G/A by PCR-SSP, but as RHD 1227A/A or A/- by melting curve analysis. These two samples were confirmed to be RHD 1227A/A or A/-. Based on RHD exon 9 sequencing, the accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of the melting curve analysis for detecting both RHD 1227A and 1227G were all 100%. In contrast, the accuracy, specificity and positive predictive value of PCR-SSP for RHD 1227G detection were 98.62%, 98.21% and 94.29%, respectively, which were lower than those observed with the melting curve analysis.ConclusionMelting curve analysis for RHD c.1227G>A genotyping is a simple, rapid, and reliable method, superior to conventional PCR-SSP.     

1 例RHD*weak D type 72 患者的血型鉴定及家系RHD 基因序列分析

目的 研究1 例RhD 血型鉴定部分凝集结果个体及其家系血清学表现和RHD 基因。方法 通过血型微柱凝胶卡检测先证者ABO 及RhD 血型;盐水试管法检测先证者及其父母RhCcEe 抗原;间接抗人球蛋白试验(indirect antihumanglobulin test,IAT) 及流式细胞术检测先证者RhD 抗原。PCR 序列特异性引物(PCR sequence specific primer, PCRSSP)检测RHD 基因以及RhD 杂合型分析,基因测序方法分析RHD 基因编码区序列。结果 血清学检测发现先证者血型为A 型RhCcee,血型微柱凝胶卡、盐水试管法以及IAT 法检测RhD 抗原,结果呈部分凝集现象。流式细胞术结果显示先证者RhD 抗原性减弱。经RHD 基因编码序列分析发现,RHD 基因第9 外显子上的第1212 位碱基发生C ＞A 纯合突变,为RHD*weak D type 72 的特征性突变点。家系调查显示,先证者父亲为O 型RhCCDee,母亲为A 型RhCcDee。父亲携带RHD*weak D type 72 等位基因,基因型为RHD*weak D type 72 / RHD+;母亲一条染色体缺失了全部的RHD 基因,基因型为RHD+/ RHD-。证明先证者分别从父亲和母亲遗传RHD*weak D type 72 和RHD-等位基因,基因型为RHD*weak D type 72 / RHD-。结论 发现了1 例RHD*weak D type 72/RHD-基因型个体,丰富了RHD*weakD type 72 变异型的研究数据。根据家系调查证明,RHD*weak D type 72 等位基因由遗传获得,而非由个体基因变异形成。     

RHD*DOL1 and RHD*DOL2 encode a partial D antigen and are in cis with the rare RHCE*ceBI allele in people of African descent

BACKGROUND: Several studies showed in people of African descent the existence of a genetic linkage between RHD alleles encoding a variant D antigen and a given altered RHCE*ce allele. RHCE*ceBI is a rare allele encountered in people of African descent, that encodes a Hr– hr^S– Rhce protein. Our study shows that RHCE*ceBI appears to be genetically linked to two very similar variant RHD alleles, RHD*DOL1 and RHD*DOL2, and demonstrates for the first time that DOL‐2 is a partial D antigen. STUDY DESIGN AND METHODS: After finding out an individual with both RHCE*ceBI and RHD*DOL presumed to be in cis, we hypothesized a genetic linkage between those two genes. All individuals (n = 7) known to carry RHCE*ceBI in our laboratory, including the index case, were fully investigated at the serologic and molecular level. RESULTS: One individual with alloanti‐D, being homozygous for RHCE*ceBI and RHD*DOL2, allowed us to confirm the genetic linkage between those two genes, as well as the partial D status of DOL‐2. In the six RHCE*ceBI remaining individuals, three were found with RHD*DOL2 and 3 with RHD*DOL1, likely in cis. Three of them made an alloanti‐D; one was DOL‐1 and two were DOL‐2. CONCLUSION: The rare RHCE*ceBI allele appears to be in cis either with RHD*DOL1 or with RHD*DOL2 in people of African descent. DOL‐1 and DOL‐2 must be considered as partial D antigens. We recommend a systematic search for RHD*DOL1 and RHD*DOL2 in people found to carry RHCE*ceBI and vice versa, especially in patients with sickle cell disease.     

A comprehensive analysis of DEL types: partial DEL individuals are prone to anti-D alloimmunization

BACKGROUND: The D antigen of the polymorphic Rh blood group system is of particular clinical importance regarding transfusion- and pregnancy-induced alloimmunization. Different RhD variants with specific clinical implications have been characterized. The least expressed D variants collectively called DEL are serologically detectable only by adsorption-elution techniques, with so far only poorly defined antigenic properties. STUDY DESIGN AND METHODS: A comprehensive immunohematologic analysis of five of the six currently known DEL genotypes was performed. DEL phenotypes associated with the RHD(M295I), RHD(IVS3+1g>a), RHD(K409K), RHD(X418L), or RHD(IVS5-38del4) allele were characterized with extended serology and flow cytometry. RESULTS: Epitope mapping with adsorption-elution revealed a prominent D epitope loss in the RHD(IVS3+1g>a)-associated DEL phenotype, whereas in the other four DEL types no signs of qualitative D antigen alteration were detected. The observation of alloanti-D in two RHD(IVS3+1g>a) cases confirmed the partial nature of this DEL phenotype. The RHD(M295I) phenotype exhibited the highest D antigen expression among all investigated DEL types, as determined by a semiquantitative adsorption-elution approach and flow cytometry. CONCLUSION: In conclusion, evidence is provided that different DEL genotypes code either for partial or complete D antigen expression and that this finding is clinically relevant.