Characterization of 104 novel alleles at the HLA-A, -B, and -DRB1 loci from National Marrow Donor Program volunteer donors

One hundred and four novel human leukocyte antigen (HLA) alleles are described from volunteer donors of the National Marrow Donor Program: 37 HLA-A alleles, 37 HLA-B alleles, and 30 HLA-DRB1 alleles. Seventeen (∼16%) of the novel alleles were found in multiple individuals and likely are relatively common in the population. Seventy-two (∼69%) of the 104 novel alleles are single nucleotide substitution variants when compared with their most homologous allele. Nine of these single nucleotide variants are silent substitutions and three create null alleles. The remaining novel alleles differ from their most similar allele by two to seven nucleotide substitutions. Some of the novel alleles encode amino acid changes at positions not previously reported to be polymorphic, such as codons 6 and 11 in HLA-A alleles and codons 5, 105, and 141 in HLA-B alleles. Interestingly, one of the novel HLA-DRB1 alleles (*1471) has a change that is not the typical glycine/valine dimorphism at codon 86, which plays a key role in peptide binding to DR molecules. This is only the second DRB1 allele described that encodes an amino acid other than glycine or valine at this position.     

Novel HLA class I and II alleles identified during routine registry typing in 2010

Twenty-one novel human leukocyte antigen (HLA) class I and class II alleles are described: seven HLA-A alleles, five HLA-C alleles, five HLA-B alleles and four HLA-DRB1 alleles. Seventeen (～81%) of the 21 novel alleles are single nucleotide substitution variants when compared with their most homologous allele. Nine of these single nucleotide variants cause an amino acid substitution, while eight are silent substitutions. The remaining novel alleles differ from their most similar allele by two to three nucleotide substitutions. One novel HLA-C locus allele encodes an amino acid change at codon 10 that previously has not been reported to be polymorphic for this locus. Some of the new alleles encode novel codons and unique amino acid changes at polymorphic positions in the HLA-A (codons 24 and 156) and HLA-B (codons 40 and 115) loci.     

Ninety-six novel HLA class I and II alleles identified in volunteers for the National Marrow Donor Program Registry in 2009

Ninety-six novel human leukocyte antigen (HLA) class I and class II alleles are described from volunteers for the 'Be The Match Registry?': 15 HLA-A alleles, 11 HLA-C alleles, 36 HLA-B alleles and 34 HLA-DRB1 alleles. Sixty-eight (～71%) of the 96 novel alleles are single nucleotide substitution variants when compared with their most homologous allele. Twenty-three of these single nucleotide variants are silent substitutions and one creates a non-expressed allele (B(*) 27:59N). The remaining novel alleles differ from their most similar allele by two to five nucleotide substitutions. One of the novel HLA-A alleles (A(*) 11:52Q) is of questionable expression because of a deletion of codon 11. Three of the novel alleles encode amino acid changes at codons 63 (HLA-C), 88 (HLA-B) and 79 (HLA-DRB1) which have not previously been reported to be polymorphic in these loci. Some of the new alleles encode novel codons and unique amino acid changes at polymorphic positions in the HLA-A (codons 115, 149 and 168), HLA-C (codon 90), HLA-B (codons 23, 44, 70, 120 and 153) and HLA-DRB1 (codon 88) loci.     

Increased HLA class I and II diversity as 72 novel alleles are identified in volunteers for the National Marrow Donor Program Registry in 2010

Seventy-two novel human leukocyte antigen (HLA) class I and class II alleles are described from volunteers for the 'Be The Match Registry?': 17 HLA-A alleles, 12 HLA-C alleles, 31 HLA-B alleles and 12 HLA-DRB1 alleles. Forty-six (≈ 64%) of the 72 novel alleles are single-nucleotide substitution variants when compared with their most homologous allele. Five of these single-nucleotide variants are silent substitutions and one creates a non-expressed allele (B*44:108N). The remaining novel alleles differ from their most similar allele by two to five nucleotide substitutions. One of the novel HLA-C alleles (C*07:150Q) is of questionable expression due to an insertion of 21 nucleotides starting at codon 143 that adds seven amino acids to exon 3. An inter-locus gene conversion may have created the novel allele HLA-A*23:31 that shares its codon differences with HLA-B*07:28. Some of the new alleles encode novel codons and unique amino acid changes at polymorphic positions in the HLA-A (codons 116 and 150), HLA-C (codon 114), HLA-B (codons 11, 21, 35, 42, 48, 73, 98 and 170) and HLA-DRB1 (codon 29) loci.     

Characterization of 236 novel alleles at the HLA-A, -B, -C, -DRB1, -DQB1 and -DPB1 loci from China Marrow Donor Program

Two hundred and thirty-six novel human leukocyte antigen (HLA) alleles are described from volunteer donors of the China Marrow Donor Program: 71 HLA-A alleles, 79 HLA-B alleles, 43 HLA-C, 16 HLA-DRB1 alleles, 26 HLA-DQB1 and 1 HLA-DPB1. Two hundred and thirteen (90.3%) of the 236 novel alleles are single nucleotide substitution variants when compared with their most homologous allele. Seventy-eight of these single nucleotide variants are silent substitutions. The remaining novel alleles differ from their most similar allele by two to four nucleotide substitutions. Some of the novel alleles encode amino acid changes at positions not previously reported to be polymorphic, such as codons 57, 62, 67, 41 and 52 in HLA-A alleles; codons 133, 156, 201 and 215 in HLA-B alleles; codons 74, 208 and 225 in HLA-C; codons 25, 32 and 72 in HLA-DRB1; codons 20, 39 and 77 in HLA-DQB1.     

Characterization of new HLA-B and -DRB1 alleles from Singapore

Six novel alleles, three human leukocyte antigen (HLA)-B and three HLA-DRB1 alleles, are described. Five of the variants are single nucleotide substitutions from their most homologous allele, of which three result in amino acid changes (B*3572, *9509 and DRB1*1157) and two are silent substitutions (B*370103 and DRB1*150204). DRB1*0462 differs by three nucleotide substitutions that alter two amino acids.     

Novel alleles at the HLA-DRB1 and -DQB1 loci

Twelve novel human leukocyte antigen class II alleles are described; eight DRB1 alleles and four DQB1 alleles. Nine of the variants are single nucleotide substitutions from their most homologous allele, of which six result in amino acid changes (DRB1*0459, *1156 and *1522; DQB1*0205, *0320 and *0321) and three are silent substitutions (DRB1*030105 and *040304, and DQB1*030104). The remaining alleles (DRB1*0906, *1464 and *1468) differ from their most similar alleles by two to three nucleotide substitutions which alter one to two amino acids.     

Seven novel HLA alleles reflect different mechanisms involved in the evolution of HLA diversity: Description of the new alleles and review of the literature

The human leukocyte antigen (HLA) loci are among the most polymorphic genes in the human genome. The diversity of these genes is thought to be generated by different mechanisms including point mutation, gene conversion and crossing-over. During routine HLA typing, we discovered seven novel HLA alleles which were probably generated by different evolutionary mechanisms. HLA-B*41:21, HLA-DQB1*02:10 and HLA-DQA1*01:12 likely emerged from the common alleles of their groups by point mutations, all of which caused non-synonymous amino acid substitutions. In contrast, a deletion of one nucleotide leading to a frame shift with subsequent generation of a stop codon is responsible for the appearance of a null allele, HLA-A*01:123N. Whereas HLA-B*35:231 and HLA-B*53:31 were probably products of intralocus gene conversion between HLA-B alleles, HLA-C*07:294 presumably evolved by interlocus gene conversion between an HLA-C and an HLA-B allele. Our analysis of these novel alleles illustrates the different mechanisms which may have contributed to the evolution of HLA polymorphism.     

新等位基因HLA-B*9526的确认和序列分析

目的 鉴定中国人群中人类白细胞抗原(human leukocyte antigen,HLA)新等位基因HLA-B*9526,并进行核苷酸序列分析.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1个反应格局异常的等位基因,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 检出反应格局异常的DNA样本,经过克隆测序得到两个等位基因,分型结果一个为B*5403,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*1507基因序列相比在第3外显子区域中425位碱基发生A→G突变,导致142位编码氨基酸由酪氨酸变成半胱氨酸.结论 一个新的HLA-B等位基因被确认,并被世界卫生组织HLA因子命名委员会正式命名为HLA-B*9526.     

A new HLA-B*40 variant, B*4073, identified by sequence-based typing in the Korean population

A novel human leukocyte antigen-B*40 (HLA-B*40) allele was identified in the Korean population and designated HLA-B*4073. The HLA-B*4073 allele shows one nucleotide difference from B*400102 in exon 2 at nucleotide position 299 (A→T), resulting in an amino acid change, Glu76Val.     

Identification of a novel HLA-B allele, HLA-B*3713, in a Chinese individual

A novel human leukocyte antigen (HLA) class I allele, HLA-B*3713, has been identified in a Chinese individual. The HLA-B*3713 allele differs from the closest matching allele B*370101 by one nucleotide substitutions in exon 3 at nt 527(T-->A), resulting in an amino acid change from Val (GTG) to Glu (GAG) at codon 152.     

HLA-B新等位基因B*9534的测序分析及其单链扩增技术的建立

目的 分析HLA-B新等位基因HLA-B*9534的核苷酸序列,并建立HLA-B * 9534单链扩增技术.方法 采用商品化快速抽提试剂盒抽提标本基因组DNA,采用PCR技术扩增先证者HLA-B基因的第1～8外显子序列,PCR产物经双酶切后直接测序分析第2、3、4外显子.应用序列特异性引物PCR建立HLA-B*9534单链扩增技术,获得HLA-B*9534等位基因的单链产物,并对单链产物进行第2、3、4外显子测序分析.结果 先证者标本存在2个HLA-B等位基因,直接测序结果经软件分析显示与最接近的HLA-B*1518和B*4601组合存在1个碱基不匹配,即第593位A/G杂合.单链扩增技术将先证者等位基因分离后,测序得到两个等位基因为HLA-B*4601和HLA-B*9534.与最接近的HLA-B*1518的第2～4外显子序列相比,HLA-B*9534仅在第3外显子存在一个碱基的不同,即第593位A→G的改变,导致第174位氨基酸天冬酰胺改变为丝氨酸,该等位基因序列已递交GenBank(EU046491),并经世界卫生组织HLA命名委员会正式命名为HLA-B*9534.结论 发现一个新的HLA-B*9534等位基因,建立的HLA-B*9534单链扩增技术是可行的.     

Identification of a novel HLA-B allele HLA-B*9526 in a Chinese donor

A novel human leukocyte antigen-B (HLA-B) allele, B*9526, was identified. The B*9526 allele has one nucleotide change from the closest matching allele B*1507 resulting in an amino acid change from Y(TAC) to C(TGC) at codon 142.     

A new HLA-B*5124 variant, B*512402 allele, identified by sequence-based typing

A novel human leukocyte antigen-B allele, officially named B*512402, was identified in a Korean bone marrow donor. The B*512402 allele shows two nucleotide substitutions compared with B*512401 in exon 3 at codons 135 (GCG → GCC) and 138 (ACC → ACG) without any amino acid substitution.     

Characterization of three novel HLA alleles, HLA-B*4613, HLA-B*4614 and HLA-B*4618, in Chinese individuals

Three novel alleles, human leukocyte antigen (HLA)-B*4613, HLA-B*4614 and HLA-B*4618, were identified in Chinese individuals. HLA-B*4613 shows four nucleotides difference from B*460101, resulting in two amino acids change from Glu to Val at codon 152 and Trp to Leu at codon 156. HLA-B*4614 has a single nucleotide difference at position 97 T→C compared with HLA-B*460101, with an amino acid change from Tyr to His at codon 9. HLA-B*4618 shares the sequence of exon 2 with B*4601 and sequences of exons 3 and 4 with B*55, B*54 or B*59, together resulting in eight amino acids change compared with HLA-B*460101.     

Identification of three novel HLA class I alleles: HLA-B*3928, HLA-B*400104 and HLA-B*4437

Three new human leukocyte antigen (HLA) class I alleles have been identified in the Tissue Typing Laboratory in Sydney, Australia. Sequence analysis of exon 2 and exon 3 of the HLA-B gene revealed the novel polymorphism. A silent substitution of C to T at nucleotide position 369 has been identified for the HLA-B*400104 allele when compared to the closest matched allele, HLA-B*400101. The HLA-B*3928 allele was identified with a nucleotide substitution of G to C at position 362 when compared to the closest matched allele, HLA-B*390101, resulting in an amino acid substitution of Arginine to Threonine. A nucleotide substitution of C to G at position 572 resulting in the amino acid change Serine to Tryptophan was identified in the new allele HLA-B*4437, when compared to the closest matched allele HLA-B*440301. Both amino acid substitutions implicate a different specificity and affinity of antigen binding for the alleles HLA-B*3928 and HLA-B*4437.     

Identification of two novel alleles HLA-B*3569 and -B*4450 and confirmation of HLA-A*2631 in the Brazilian population

Two novel alleles, human leukocyte antigen (HLA)-B*3569, -B*4450 and a confirmatory sequence of HLA-A*2631 were identified during a routine typing for the Brazilian Bone Marrow Donor Registry. Sequence analysis of coding exons 2 and 3 revealed a single nucleotide substitution in HLA-B*3569 and two single nucleotide substitutions in HLA-B*4450, compared with closely related alleles. At the protein level, these substitutions result in a change of a single amino acid residue in each of HLA-B*3569 and -B*4450 at positions 74 (Arg > Pro) and 80 (Thr > Ile), respectively. These variations are located in the highly polymorphic region at the end of the alpha(1) domain of the HLA molecule. It appears that HLA-B*3569 arose from the analogous HLA-B*3510 through a point mutation. However, HLA-B*4450 may have arisen from HLA-B*440301 and -B*4425 by gene conversion.     

Expanding diversity at the HLA-B locus: 28 novel HLA-B alleles

Twenty-eight novel human leukocyte antigen-B alleles are described: one B*07 (*0745), two B*08 (*0826 and *0831), one B*27 (*2731), four B*35 (*350106, *350402, *3566, and *3568), two B*37 (*370102 and *3711), two B*38 (*380102 and *3813), two B*39 (*3935 and *3939), one B*41 (*4108), one B*42 (*4209), two B*44 (*4444 and *4448), two B*48 (*480302 and *4815), one B*51 (*5140), one B*55 (*5523), one B*56 (*5617), two B*57 (*570103 and *5710), and three B*15 (*9505, *9510, and *9519). Sixteen of the variants are single-nucleotide substitutions from their most homologous allele, of which 10 result in amino acid changes (B*0745, *0831, *3813, *3935, *3939, *4815, *9505, *9509, *9510, and *9519) and 6 are silent substitutions. The remaining alleles (B*0826, *2731, *3566, *3568, *3711, *4108, *4209, *4444, *4448, *5140, *5523, *5617, and *5710) differ from their most similar alleles by two to seven nucleotides substitutions, altering from one to five amino acids.     

Identification of a new HLA-B*08 variant, HLA-B*0804

The HLA-B locus is the most polymorphic locus known with currently over 100 different alleles described. Many of these alleles encode variants of the serologically-defined tissue transplantation antigens. This high level of diversity makes accurate tissue typing difficult. Here we present the sequence of a new HLA-B *08 variant, HLA-B *0804. found in Caucasian siblings JH and PF serologically typed as HLA-B51/B59 and HLA-B59/B60, respectively. Additionally, DNA-based typing by the polymerase chain reaction using sequence-specific primers (PCR-SSP) identified HLA-B *51 in JH and HLA-B *4001 in PF. However, PCR-SSP failed to identify a second allele in either of these individuals. The unusual finding of a B59 antigen in a Caucasian and the discrepant molecular typing results suggested that these individuals might express novel HLA molecules. Using denaturing gradient gel electrophoresis (DGGE) followed by direct sequencing, we characterized a novel HLA-B *08 variant, HLA-B *0804. The presence of this allele was confirmed by cloning and sequencing. HLA-B *0804 differed from HLA-B *0801 by only one nucleotide substitution resulting in an amino acid replacement of phenylalanine by serine at position 67. Incidentally, this single nucleotide difference was sufficient to prevent amplification by PCR-SSP. This striking difference between both the serologically typed antigen and the PCR-SSP-identified allele compared to the sequenced allele supports the use of sequence-based typing for the analysis of HLA class I locus alleles.     

HLA-B allele frequencies in Côte d'Ivoire defined by direct DNA sequencing: identification of HLA-B*1405, B*4410, and B*5302

Direct automated DNA sequencing was used to analyze exons 2 and 3 of HLA-B alleles present in forty-four unrelated individuals residing in the village of Adiopodoume, C?te d'Ivoire (Ivory Coast). Of the 23 HLA-B alleles observed, the most frequently detected allele was HLA-B*5301 (22.7%), which is believed to confer resistance to severe Plasmodium falciparum malaria. B*4501 (9.1%), B*1503 (8.0%), B*0705 (5.7%), B*1510 (5.7%) and B*3501 (5.7%) occurred frequently in the population. A second allele of B53 was identified; B*5302 contains a single amino acid variation at residue 171 (Y-->H). Two additional novel alleles, B* 1405 (a single amino acid variant of B*1402) and B*4410 (a five amino acid variant of B*4403) were characterized.