Characterization of HLA-B*3921 and confirmation of HLA-B*4415, two variant HLA-B alleles identified in the Omani population

We describe a variant HLA-B*39 allele present in two individuals from Oman, which has been officially named HLA-B*3921. In addition we confirm the existence of HLA-B*4415, an allele closely related to HLA-B*4501 differing only at the Bw4/Bw6 epitope.     

Complete coding sequences and haplotypic associations of HLA-B*0707, -B*1524, -B*4405, -B*4802, -DRB1*0409, -DRB1*0411, -DRB1*1115, -DRB1*1305, and the novel allele -DRB1*0709. Group-specific amplification of cDNA from DRB1 alleles associated to DRB3 and DRB4

We present here the characterization of the complete coding sequences, previously unavailable, of the human leukocyte antigen (HLA) alleles B*0707, B*1524, B*4405, B*4802, DRB1*0409, DRB1*0411, DRB1*1115, DRB1*1305, and that of a new allele, DRB1*0709. For the isolation of cDNA from the DRB1 gene, we designed a novel set of polymerase chain reaction (PCR) primers that makes it possible to amplify separately the groups of DRB1 alleles associated to each of the DRB3 and DRB4 loci. The primary structures, functional features, evolutionary relationships, haplotypic associations, and population distributions of each of the nine HLA-B and -DRB1 alleles reported here are reviewed.     

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.     

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.     

Human leukocyte antigen-A, -B, and -DRB1 alleles and sarcoidosis in Chinese Han subjects

Human leukocyte antigens (HLA) play a key role in antigen presentation. HLA genes, especially HLA-A, -B, and -DRB1, which are highly polymorphic, have been thought to be candidate loci for the etiology of sarcoidosis. This study aimed to assess the association between the polymorphism of HLA-A, -B, and -DRB1 alleles and sarcoidosis in Chinese Han subjects. Genomic DNA was extracted from 131 patients with sarcoidosis and 122 healthy controls. The polymorphisms of the HLA-A, -B, and -DRB1 alleles were determined using a polymerase chain reaction sequence-specific primer method. The frequency of allele HLA-DRB1*11 in sarcoidosis patients was significantly higher than that in controls (24.43% vs 4.92%, p/p_c = 0.0001/0.002), whereas the frequencies of allele HLA-B*13 and HLA-DRB1*07 were markedly lower in sarcoidosis patients than in controls (12.21% vs 27.87%, p/p_c = 0.002/0.045; 7.63% vs 22.95%, p/p_c =0.001/0.009). HLA-B*51 was overrepresented in patients with erythema nodosum and Löfgren's syndrome (p < 0.001 [p_c = 0.015], p < 0.0001 [p_c < 0.001], respectively). These results support the hypothesis that HLA-A, -B, and -DRB1 polymorphisms may play a role in susceptibility and manifestation of sarcoidosis.     

HLA-B*9518 allele identified in the Chinese population

We report here a novel HLA-B*9518 allele by sequence-based typing in the Chinese population. The new B*9518 is identical to B*150101 with an exception of one base substitution at position 19 of exon 3 where a 'G' change to 'T' resulting in codon 97 changed from AGG (Arg) to ATG (Met).     

HLA-A, -B, -C, -DRB1 and -DQB1 alleles and haplotypes in the Kinh population in Vietnam

Allele and haplotype frequencies of the human leukocyte antigens (HLA) were studied in the Kinh Vietnamese population. We analyzed 170 unrelated healthy individuals. DNA-based HLA typing was performed using a microsphere-based array genotyping platform with sequence-specific oligonucleotide probes to distinguish HLA-A, -B, -C, -DRB1 and -DQB1 alleles. A total of 21 HLA-A, 37 HLA-B, 18 HLA-C, 25 HLA-DRB1, and 14 HLA-DQB1 alleles were identified. HLA-A*1101, A*2402, A*3303, B*1502, B*4601, Cw*0102, Cw*0702, Cw*0801, DRB1*1202, DQB1*0301, DQB1*0303, and DQB1*0501 were found with frequencies higher than 10%. Two representative haplotypes bearing two to five HLA loci were A*1101-B*1502 and A*3303-B*5801 for HLA-A-B; Cw*0801-B*1502 and Cw*0102-B*4601 for HLA-C-B; B*1502-DRB1*1202 and B*4601-DRB1*0901 for HLA-B-DRB1; DRB1*1202-DQB1*0301 and DRB1*0901-DQB1*0303 for HLA-DRB1-DQB1; A*1101-Cw*0801-B*1502 and A*3303-Cw*0302-B*5801 for HLA-A-C-B; A*1101-B*1502-DRB1*1202 and A*2901-B*0705-DRB1*1001 for HLA-A-B-DRB1, A*1101-Cw*0801-B*1502-DRB1*1202-DQB1*0301 and A*2901-Cw*1505-B*0705-DRB1*1001-DQB1*0501 for HLA-A-C-B-DRB1-DQB1. Allele distribution and haplotype analysis demonstrated that the Vietnamese population shares HLA patterns with southern Chinese, Thai, Javanese and Micronesians, while it also retains unique characteristics.     

Two novel alleles HLA-B*9536 and B*4612 were identified in a healthy Chinese individual

The novel HLA-B*9536 and B*4612 alleles were identified by sequence-based typing in China.     

Characterisation of a new HLA-B allele, HLA-B*0720, identified in the Cuban population

The HLA class I genes display significant levels of polymorphism, which is principally due to hypervariable regions located in the second and third exons. To date, 286 HLA-B alleles have been identified and characterised. We describe a new HLA-B*07 allele present in a Cuban Caucasoid individual, which has been officially named HLA-B*0720.     

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.     

HLA-A, -B and -DRB1 allele frequencies in the Bangladeshi population

Population genetic studies have become an invaluable tool because of the extreme polymorphism found at some of the loci of the human leukocyte antigen (HLA) system. In this study, we are reporting for the first time the genetic polymorphism of 141 healthy unrelated Bangladeshi Bangalees living in central region of Dhaka. We studied the HLA-A, -B and -DRB1 loci using polymerase chain reaction with sequence-specific primers. The allelic frequencies, two and three locus haplotype frequencies were statistically analyzed. A total of 16 HLA-A alleles, 26 HLA-B alleles and 14 HLA-DRB1 alleles were detected. A*33-B*44 (8.15%) was the most common two loci class 1 haplotype, whereas A*33-B*44-DRB1*07 (6.38%) was the most frequent three loci haplotype. The most common HLA-A, HLA-B and HLA-DRB1 alleles were A*33 (17.02%), B*15 (19.5%) and DRB1*15 (29.07%), respectively. Construction of phylogenetic tree using average linkage between groups and correspondence analysis showed close associations with Indian non-tribal random Dravidians, north Indian Hindus and some relations with Mongolian and Pakistani populations. We believe this data will provide useful information for bone marrow registry, legal medicine, disease association and anthropological studies.     

Distribution of HLA-A, -B, -Cw, and -DRB1 alleles and haplotypes in an isolated Han population in Southwest China

In this study, polymorphisms of human leukocyte antigen (HLA) class I (A, B, and Cw) and class II (DRB1) loci were analyzed in an isolated Han population living in Fengyandong in the Yunnan province of Southwest China (FYDH) using a high-resolution polymerase chain reaction–Luminex typing method. A total of 13 A, 26 B, 15 Cw, and 23 DRB1 alleles of HLA were found in FYDH. The frequencies of A*1101, A*0207, A*2402, B*4601, B*1502, Cw*0102, Cw*0801, DRB1*0901, and DRB1*1202 were >10%. The following haplotypes were common with frequencies >5%: three A-B, four Cw-B, two B-DRB1, two A-B-DRB1, three A-B-Cw, two B-Cw-DRB1, and two A-B-Cw-DRB1 phylogenetic tree and multidimensional scaling analysis based on HLA-A, -B, and -DRB1 allele frequencies of 18 Han populations suggested that FYDH was an isolated Han population, but the analytic result also provided a suggestion that FYDH was genetically related to Chinese Southern Han. According to the characteristics of the HLA allele and haplotype distributions and significantly reduced allelic and haplotypic diversity in FYDH, we deduced that genetic drift and/or selection and subsequent geographic isolation had influenced the distribution characteristics of the HLA gene in FYDH. In addition, significantly reduced allelic and haplotypic diversity in FYDH makes it an ideal homogenous population and very useful model for future investigations of issues related to immunogenetic diseases in the Han population.     

Characterization of two new HLA-B alleles by sequence-based typing: HLA-B*0817 and HLA-B*1311

In this brief communication we report the characterization of two new HLA-B variants officially named HLA-B*0817 and HLA-B*1311. The HLA-B*0817 allele was identified in a Caucasoid male candidate for renal transplantation in the North Italy Transplant program. The nucleotidic sequence of exons 2, 3 and 4 of this novel allele is identical to that of HLA-B*0804 except for three point mutations in exon 2: from A to G at position 259, from C to G at position 261 and from G to A at position 302. These mutations are responsible for two aminoacidic substitutions [Asn (r) Glu, codon 63, and Ser (r) Asn, codon 77]. HLA-B*1311 was found in a volunteer donor belonging to National Marrow Donor Program(R). This new variant is identical to that of HLA-B*1301 except for three nucleotide substitutions at positions 353, 355 and 369 leading to two aminoacidic variations from Ile to Thr at codon 94 and from Ile to Leu at codon 95 and a silent mutation at codon 99.     

西北地区汉族人群HLA-A、-B、-DRB1基因座单倍型分析

目的 分析西北地区汉族群体HLA-A、-B和-DRB1基因座等位基因频率和HIA-A-B、B-DRB1和A-B-DRB1单倍型，获得单倍型频率数据。方法 采用序列特异性寡核苷酸探针反向斑点杂交技术对西北地区62个家系和101个无关个体HLA-A、-B和-DRB1基因座进行基因分型，分析HLA单倍型。结果 在西北地区汉族人群中检出15个HLA-A等位基因，28个HLA-B等位基因，13个HLA-DRB1等位基因，A02、A11、A24、B13、B15、1340、DRB1＊04、DRB1＊07、DRB1＊09和DRB1＊15基因频率较高（〉10％），A02（0．3244）、B13（0．1200）和DRB1＊15（0．1400）等位基因频率最高。分析得出HLA-A-B、B-DRB1、A-B-DRB1单倍型分别有122、147和278种，83种A-B-DRB1单倍型有至少两条以上相同的单倍型，占总单倍型数的18．44％（83／450）。A30-B13-DRB1＊07、A02-B46-DRB1＊09、A01-B37-DRB1＊10、A24-B15-DRB＊15、A02-B46-DRB1＊08、A33-B58-DRB1＊03是最常见的单倍型。结论 西北地区汉族群体HLA单倍型多态性较为丰富，等位基因频率和单倍型频率数据可用于骨髓移植供者的选择、法医学亲权鉴定以及人类学研究。