α1，3半乳糖基转移酶基因721C〉T突变导致Bw亚型

目的研究红细胞ABO血型系统Bw亚型的分子基础. 方法通过标准血型血清学方法明确鉴定2个家庭3例Bw亚型,PCR扩增Bw亚型ABO糖基转移酶基因的增强子、启动子和第1～7外显子及侧翼内含子序列,PCR产物经割胶纯化后直接测序.同时将第6和7外显子克隆到pcDNA3.1(-)质粒,转化DH5α后进行序列分析.采用序列特异性引物-聚合酶链反应方法证实测序所发现的突变.结果直接测序发现3例Bw亚型的基因型为B/O杂合,其中糖基转移酶基因的第261位G杂合缺失,第721位C/T杂合.克隆证实一条染色体上为正常的O等位基因,另一条染色体上B等位基因(α1,3半乳糖基转移酶基因)存在第721位C>T突变,导致多肽链Arg241Trp替换.序列特异性引物-聚合酶链反应检测140份随机样本未发现此突变. 结论α1,3半乳糖基转移酶基因第7外显子721C>T突变可能是Bw亚型分子遗传基础之一.     

一种新的B3变异型相关的B糖基转移酶基因M142T突变研究

目的 研究中国人个体ABO血型系统中具有混合外观凝集特征的B3变异型的分子遗传背景.方法 血型血清学方法鉴定2例ABO血型疑难样本的红细胞表型,应用连续凝集方法和13个短串联重复序列(short tandem repeat,STR)位点检测法,排除外源性或内源性DNA嵌合的可能.对ABO基因第6、7外显子和部分内含子进行聚合酶链反应和DNA序列分析,并进一步通过克隆测序法鉴定2个样本的ABO基因单倍型.结果 2个无关个体红细胞与抗-B和抗-AB发生混合外观凝集,连续凝集法和STR检测排除了样本的外源性DNA污染和内源性遗传嵌合子,根据血清学特征确定这2个个体红细胞均为A183血型.单倍型序列分析发现2个样本为A1B杂合子,其中B等位基因与B101相比,差异仅在第7外显子的425T>C错义突变,导致B糖基转移酶多肽链M142T替换.结论 在中国人群中发现一种新的可能导致B3变异型的ABO等位基因.     

Identification of the novel allele HLA-B*4076 by sequence-based typing in a Chinese individual

A novel human leukocyte antigen-B allele, officially named B*4076 allele, was found in a potential Chinese bone marrow donor when direct sequence-based typing was carried out. The novel B*4076 is identical to B*400101 with an exception of one base substitution at position 239(C>A)of exon 2 resulting in codon #80 changed from AAC (Asn) to AAA (Lys).     

新等位基因人类白细胞抗原B*4609的发现和确认

目的 鉴定一个人类白细胞抗原(human leukocyte antigen,HLA)新等位基因HLA-B*4609.方法 使用序列特异性寡核苷酸PCR技术进行HLA基因分型,发现反应格局异常的可疑新等位基因,应用分子克隆和DNA双向测序技术测定新等位基因的核苷酸序列,并与已知等位基因进行序列比对分析.结果 检出1个样本HLA-B位点反应格局异常,DNA测序分型结果一个为B*151101,另一个的核苷酸序列与已知的HLA等位基因均不同,该基因序列与同源性最高的HLA-B*460101基因序列相比,在第3外显子区域中527位碱基发生A→T突变,导致176位编码氨基酸由谷氨酸(GAG)变成缬氨酸(GTG).结论 样本中含有HLA-B新等位基因序列.该序列申报后,被世界卫生组织HLA因子命名委员会正式命名为HLA-B*4609.     

Sequence analysis of the novel HLA-Cw*08 variant allele, Cw*0820, in a Chinese Han individual

A novel human leukocyte antigen (HLA) allele, HLA-Cw*0820, was identified in a Chinese Han individual. It differs from the closest allele Cw*080101 by single nucleotide change at genomic nucleotide (nt) 1615 G>A (coding sequence nt 652 G>A, codon 194 GTC>ATC) in exon 4, which results in an amino acid change Val194Ile.     

Identification of a novel B variant allele at the ABO locus in Chinese Han individuals with B subgroup

We studied the molecular genetic background of the B subgroup in the Chinese Han population and identified a novel allele at the ABO locus. Ten control samples from randomly selected blood donors of normal B phenotype and 6 samples from individuals diagnosed as B subgroup by serological tests were genotyped by PCR-SSP and direct DNA sequencing at exons 6 and 7 of the ABO gene. Exons 6 and 7 and the intervening intron 6 of B alleles from the 6 B subgroup samples were analyzed by cloning and haplotype-sequencing. A novel B variant allele was identified in 2 individuals who were serologically-determined as members of the B(x) and B(w) subgroups, respectively. The novel B allele differs from allele B101 by a single 695T>C missense mutation in exon 7. The family of the individual with B(x) subgroup was studied; among 8 family members tested, 4 had the novel B variant allele. No mutation at exon 6 or 7 of the ABO gene was detected in the 10 control samples or in the other 4 B subgroup samples. Mutation at position 695 where T is replaced by C results in an amino acid change from Leu to Pro, which is predicted to diminish B transferase activity. This indicates that alteration of the amino acid at position 232 is critical to the activity of glycosyltransferases.     

一例ABO血型重组等位基因的分子特性

目的分析一例ABO血型重组等位基因的分子特性。方法ABO表型鉴定采用试管法。ABO基因和FUT1基因编码区序列检测采用PCR测序法。利用等位基因特异性引物扩增测序技术鉴别先证者ABO等位基因。先证者及其母亲ABO基因全长序列测定采用二代测序方法。结果先证者红细胞与抗H不凝集,FUT1基因为c.551_552del AG纯合,判定先证者为类孟买型。先证者ABO基因双链测序结果为c.261G/del、467C>T、c.526C>G、c.657C>T、c.703G>A、c.796C>A、c.803G>C、c.930G>A杂合。单链测序结果显示先证者有一个ABO*A1.02等位基因,另一个为ABO*O.01.01和ABO*B.01重组形成的等位基因。二代测序数据显示可能重组的位置在核苷酸c.375-269到c.526之间,家系分析显示先证者重组等位基因遗传自母亲。结论ABO血型等位基因存在重组现象。发现了1例ABO*O.01.01和ABO*B.01重组形成的新等位基因。     

一例ABO新等位基因B112的分子生物学研究及其家系分析

目的 研究1例新的ABO亚型B112的分子机制,并对其家系进行分析.方法 应用单克隆抗体检测先证者红细胞ABO血型抗原,标准A、B、O红细胞检测先证者血清中的ABO抗体.采用聚合酶链反应(po1ymerase chain reaction,PCR)技术扩增先证者ABO基因的第5至7外显子序列,PCR产物经双酶切后直接测序分析第6和7外显子.同时采用基因组单链抽提技术分离先证者的两条单倍型,对分离的单倍型扩增后进行ABO基因测序分析.家系调查采集先证者父母的标本进行ABO血清学实验和ABO基因第6和7外显子测序分析.结果 先证者血清学表型符合B表型特性,直接测序分析显示第6和7外显子有261G/缺失、297A/G、526C/G、559C/T、657C/T、703G/A、796C/A、803G/C、930G/A杂合,推断基因型为BO.基因组单链抽提技术将先证者B和O基因分离后,测序得到两个等位基因为O01和B112.与B101相比,B112第559位C→T导致第187位精氨酸变成半胱氨酸.家系调查显示先证者B112基因从母亲遗传所得,母亲标本ABO血型血清学特性和测序分析结果与先证者完全一致.结论 发现1例559C＞T突变的ABO亚型新等位基因B112,其B抗原表达正常,提示α-1,3-半乳糖基转移酶第187位精氨酸变成半胱氨酸并不影响B转移酶的活性.     

一例新的HLA-B等位基因B*5614的核苷酸序列分析

目的 研究HLA新的等位基因HLA-B*5614的分子基础。方法 样本DNA抽提采用盐析法，利用PCR方法扩增先证者HLA-B基因的第2～4外显子，PCR产物直接经TOPO转染克隆到质粒载体中分离其等位基因，对所得克隆进行第2～4外显子双向测序分析。应用序列特异性引物PCR方法证实测序所发现的突变。结果 先证者样本克隆测序得到两个等位基因，其中1个等位基因为B*1502，另一个经BLAST验证为新的等位基因，新的等位基因序列已递交GenBank(AY601726，AY601727，AY601728)。与最接近的B*5608等位基因序列相比，新的等位基因仅在第2外显子上有1个核苷酸不同，即第277位G→C，导致第93位氨基酸Cly→Arg。结论 该等位基因为新的HLA-B等位基因，被世界卫生组织HLA因子命名委员会正式命名为HLA-B*5614。     

人类白细胞抗原新等位基因DRB1*1219的确认及其序列分析

目的 鉴定分析1个白血病患者家庭HLA-DRB1位点1个新等位基因.方法 应用PCR-序列特异性引物及Luminex DNA杂交流式分型技术进行HLA分型,发现1个与HLA-DRB1*120201相关的未知基因.应用DNA测序技术进行鉴定分析并与已知序列比对分析.结果 先证者DRB1位点有1个等位基因的核苷酸序列与所有已知基因序列均不相同,与同源性最高的DRB1*120201相比,第2外显子第341位核苷酸碱基发生了C→T,结果导致相应85位密码子编码的丙氨酸变为缬氨酸.结论 测序表明被测样本含有1个HLA-DRB1新等位基因,被世界卫生组织HLA因子命名委员会正式命名为HLA-DRB1*1219(序列号EJ374889).

Abstract：

Objective To identify a novel HLA DRB1 allele in a Chinese leukemia family. Methods A new HLA-DRB1 allele was initially detected by polymerase chain reaction-sequence specific primer and unusual reaction pattern by Luminex RSSO, then DNA sequencing was performed to identify the sequence of the novel allele. Results The DNA sequencing revealed the presence of the new allele which differs from the closest macthing HLA- DRB1 * 120201 by a single nucleotide substitution at position (341 C→T in exon 2),resulting in an amino acid change from Ala to Val at coden 85. Conclusion A novel allele was confirmed by DNA sequencing and has been designated HLA-DRB1 * 1219 by the WHO Nomenclature Committee.     

Haplotype-specific sequencing reveals a novel HLA-B*37 allele, B*3714

We report on a novel human leukocyte antigen (HLA)-B allele, HLA-B*3714. This allele differs from HLA-B*3711 by two nucleic acid substitutions at positions 317 and 319 in exon 2, both resulting in amino acid exchanges. The first one leads to the exchange from arginine to leucine at position 82, and the latter one from glycine to arginine at position 83.