Discovery of the rare HLA‐B*39:77 allele in an unrelated Taiwanese bone marrow stem cell donor using the sequence‐based typing method

We detected a rare HLA‐B locus allele, B*39:77, in a Taiwanese unrelated marrow stem cell donor in our routine HLA sequence‐based typing (SBT) exercise for a possible haematopoietic stem cell donation. In exons 2, 3 and 4, the DNA sequence of B*39:77 is identical to the sequence of B*39:01:01:01 except one nucleotide at nucleotide position 733 (G‐>A) in exon 4. The nucleotide variation caused one amino acid alteration at residue 221 (Gly‐>Ser). B*39:77 was probably derived from a nucleotide substitution event involving B*39:01:01:01. The probable HLA‐A, ‐B, ‐C, ‐DRB1 and ‐DQB1 haplotype in association with B*39:77 may be deduced as A*02:01‐B*39:77‐C*07:02‐DRB1*08:03‐DQB1*06:01. Our discovery of B*39:77 in Taiwanese adds further polymorphism of B*39 variants in Taiwanese population.     

Identification of the novel HLA‐B*40:221 allele in a Taiwanese hematopoietic stem cell donor using a sequence‐based typing method

Using DNA sequence‐based typing method, we found a new HLA‐B*40 variant, B*40:221, in a Taiwanese hematopoietic stem cell donor. The allele sequence of B*40:221 is identical to the sequence of B*40:01:01 in exons 2, 3 and 4 except the nucleotides at codon 265 (GGG→AGG). The sequence variation caused one amino acid exchange at residue 265 where Gly was replaced by Arg. The probable HLA‐A, ‐B, ‐C, ‐DRB1 and ‐DQB1 haplotype in association with B*40:221 may be deduced as HLA‐A*11:01‐B*40:221‐C*03:04‐DRB1*14:54‐DQB1*05:02. The generation of B*40:221 is thought as a result of a nucleotide point mutation involving B*40:01:01. Our discovery of B*40:221 increases the polymorphism of B*40 in Taiwanese.     

Discovery of a novel HLA‐DRB1*04:05 variant,DRB1*04:05:15, in a Taiwanese and the probable HLA haplotype in association with DRB1*04:05:15

Here, we report a novel HLA‐DRB1*04 allele, DRB1*04:05:15, found in a Taiwanese unrelated volunteer bone marrow hematopoietic stem cell donor by a sequence‐based typing (SBT) method. The DNA sequence of DRB1*04:05:15 is identical to the sequence of DRB1*04:05:01 in exon 2, except the nucleotide at the position 198 where C is substituted by T (TAC→TAT at codon 37). Due to the silent mutation, the nucleotide replacement generated no amino acid variation in comparison with DRB1*04:05:01. We postulate the allele DRB1*04:05:15 was probably derived from DRB1*04:05:01 via a nucleotide point mutation event. The probable HLA‐A, ‐B, ‐C, ‐DRB1 and ‐DQB1 haplotype in association with DRB1*04:05:15 may be deduced as A*02:01‐B*48:01‐C*08:03‐DRB1*04:05:15‐DQB1*04:01.     

Recognition of a Caucasoid HLA‐B locus allele,B*44:55, in a Taiwanese/Chinese bone marrow stem cell donor

We detected a Caucasoid HLA‐B allele, HLA‐B*44:55, in a potential Taiwanese/Chinese bone marrow hematopoietic stem cell donor during our routine HLA SBT (sequence‐based typing) practice. The sequence of B*44:55 varies with B*44:02:01:01 with one nucleotide in exon 2 at position 97 (T‐>C), while it differs from B*44:03:01 with one nucleotide in exon 2 at position 97 (T‐>C) and three nucleotides in exon 3 at residues 538–540 (CTG‐>GAC). The nucleotide replacements caused one amino acid variation with B*44:02:01:01 at residue 9 (Y‐>H) and two amino acid variations with B*44:03:01 at residue 9 (Y‐>H) and residue 156 (L‐>D). The formation of B*44:55 is probably the result of a nucleotide substitution involving B*44:02:01:01 at position 97 (T‐>C). The Taiwanese/Chinese donor with B*44:55 claims having no kinship with Caucasian. Our speculations on the origin of the Taiwanese/Chinese B*44:55 will be presented.     

Discovery of HLA‐DRB1*03:20 allele in a Taiwanese volunteer hematopoietic stem cell donor and the probable HLA‐A, ‐B, ‐C and ‐DRB1 haplotype in association with DRB1*03:20

The allele HLA‐DRB1*03:20, a variant of DRB1*03, was first reported to the IMGT HLA database in April 2001 without indication on the ethnicity of the blood donor (Cell ID: HC 125775). We found a Taiwanese volunteer hematopoietic stem cell donor carries DRB1*03:20 by a sequence‐based typing (SBT) method. The DNA sequence of DRB1*03:20 is identical to the sequence of DRB1*03:01:01 in exon 2, except a nucleotide substitution at position 341(T→C) (GTT→GCT at codon 85). The nucleotide replacement produced an amino acid variation at residue 85 (V→A). We hypothesize that DRB1*03:20 was probably derived from DRB1*03:01:01 via a nucleotide point mutation event. The probable HLA haplotype in association with DRB1*03:20 was deduced as A*11:02‐B*58:01‐C*07:02‐DRB1*03:20. We here report the Taiwanese/Chinese ethnicity of DRB1*03:20.     

The distributions of HLA‐A,HLA‐B,HLA‐C,HLA‐DRB1 and HLA‐DQB1 allele and haplotype at high‐resolution level in Zhejiang Han population of China

The distributions of HLA allele and haplotype are variable in different ethnic populations and the data for some populations have been published. However, the data on HLA‐C and HLA‐DQB1 loci and the haplotype of HLA‐A, HLA‐B, HLA‐C, HLA‐DRB1 and HLA‐DQB1 loci at a high‐resolution level are limited in Zhejiang Han population, China. In this study, the frequencies of the HLA‐A, HLA‐B, HLA‐C, HLA‐DRB1 and HLA‐DQB1 loci and haplotypes were analysed among 3,548 volunteers from the Zhejiang Han population using polymerase chain reaction sequencing‐based typing method. Totals of 51 HLA‐A, 97 HLA‐B, 45 HLA‐C, 53 HLA‐DRB1 and 27 HLA‐DQB1 alleles were observed. The top three frequent alleles of HLA‐A, HLA‐B, HLA‐C, HLA‐DRB1 and HLA‐DQB1 loci were A*11:01 (23.83%), A*24:02 (17.16%), A*02:01 (11.36%); B*40:01 (14.08%), B*46:01 (12.20%), B*58:01 (8.50%); C*07:02 (18.25%), C*01:02:01G (18.15%), C*03:04 (9.88%); DRB1*09:01 (17.52%), DRB1*12:02 (10.57%), DRB1*15:01 (9.70%); DQB1*03:01 (22.63%), DQB1*03:03 (18.26%) and DQB1*06:01 (10.88%), respectively. A total of 141 HLA‐A‐C‐B‐DRB1‐DQB1 haplotypes with a frequency of ≥0.1% were found and the haplotypes with frequency greater than 3% were A*02:07‐C*01:02:01G‐B*46:01‐DRB1*09:01‐DQB1*03:03 (4.20%), A*33:03‐C*03:02‐B*58:01‐DRB1*03:01‐DQB1*02:01 (4.15%), A*30:01‐C*06:02‐B*13:02‐DRB1*07:01‐DQB1*02:02 (3.20%). The likelihood ratios test for the linkage disequilibrium of two loci haplotypes was revealed that the majority of the pairwise associations were statistically significant. The data presented in this study will be useful for searching unrelated HLA‐matched donor, planning donor registry and for anthropology studies in China.     

Study on the polymorphisms of HLA‐ABCDQB1DRB1 alleles and haplotypes in Hubei Han population of China

The present study aimed to analyse the frequencies of human leukocyte antigen HLA‐ABCDQB1 and HLA‐DRB1 alleles and haplotypes in a subset of 3,732 Han population from Hubei of China. All samples were typed in the HLA‐ABCDQB1 and HLA‐DRB1 loci using the sequence‐based typing method; subsequently, the HLA polymorphisms were analysed. A total of 47 HLA‐A, 89 HLA‐B, 43 HLA‐C, 49 HLA‐DRB1 and 24 HLA‐DQB1 alleles were identified in the Hubei Han population. The top three most frequent alleles in the HLA‐ABCDQB1 and HLA‐DRB1 were A*11:01 (0.2617), A*24:02 (0.1590), A*02:07 (0.1281); B*46:01 (0.1502), B*40:01 (0.1409) and B*58:01 (0.0616); C*01:02 (0.2023), C*07:02 (0.1691) and C*03:04 (0.1175); and DQB1*03:01 (0.2000), DQB1*03:03 (0.1900), DQB1*06:01 (0.1187); DRB1*09:01 (0.1790), DRB1*15:01 (0.1062) and DRB1*12:02 (0.0841), respectively. Meanwhile, the three most frequent two‐loci haplotypes were A*02:07‐C*01:02 (0.0929), B*46:01‐C*01:02 (0.1366) and DQB1*03:03‐DRB1*09:01 (0.1766). The three most frequent three‐loci haplotypes were A*02:07‐B*46:01‐C*01:02 (0.0883), B*46:01‐DQB1*03:03‐DRB1*09:01 (0.0808) and C*01:02‐DQB1*03:03‐DRB1*09:01 (0.0837). The three most frequent four‐loci haplotypes were A*02:07‐B*46:01‐C*01:02‐DQB1*03:03 (0.0494), B*46:01‐DRB1*09:01‐C*01:02‐DQB1*03:03 (0.0729) and A*02:07‐B*46:01‐DQB1*03:03‐DRB1*09:01 (0.0501). The most frequent five‐loci haplotype was A*02:07‐B*46:01‐C*01:02‐DQB1*03:03‐DRB1*09:01 (0.0487). Heat maps and multiple correspondence analysis based on the frequencies of HLA specificity indicated that the Hubei Han population might be described into Southern Chinese populations. Our results lay a certain foundation for future population studies, disease association studies and donor recruitment strategies.     

Immunogenetics of three novel HLA‐Class II alleles: DRB1*03:112, DQB1*03:02:16 and DQB1*03:139

Three novel HLA‐Class II alleles, DRB1*03:112, DQB1*03:02:16 and DQB1*03:139, are described with predicted bearing haplotypes of A*02:01, B*40:01, C*03:04, DRB1*03:112, DQB1*02:01; A*23:01, B*15:01, C*03:03, DRB1*04:01, DQB1*03:02:16 and A*01:01, B*44:02, C*05:01/03, DRB1*04:01, DQB1*03:139. Serological tests showed that the DRB1*03:112 and DQB1*03:139 specificities failed to react as expected with some well‐documented monoclonal antibodies. Subsequent examination of published HLA‐Class II epitopes and inspection of amino acid motifs suggested that epitopes exist that include the positions of their single substitutions (F31C between DRB1*03:01:01:01 and DRB1*03:112, and R48P between DQB1*03:01:01:01 and DQB1*03:139 specificities). This suggests that the reactivity of the monoclonal antibodies used was dependent on these epitopes and that their loss from these rare allele products resulted in their aberrant serology. The new alleles were found after the sequence‐based typing of 32 530 random UK European routine blood donors suggesting that each has a maximum carriage frequency of 0.0031% in the blood donor population resident in Wales.     

HLA‐A, ‐B and ‐DRB1 allele and haplotype frequencies of 8333 Chinese Han from the Zhejiang province,China

The distribution of human leucocyte antigen (HLA) allele and haplotype is varied among different ethnic populations. In this study, HLA‐A, ‐B and ‐DRB1 allele and haplotype frequencies were determined in 8333 volunteer bone marrow donors of Zhejiang Han population using the polymerase chain reaction sequence‐based typing. A total of 52 HLA‐A, 96 HLA‐B and 61 HLA‐DRB1 alleles were found. Of these, the top three frequent alleles in HLA‐A, HLA‐B and HLA‐DRB1 loci, respectively, were A*11:01 (24.53%), A*24:02 (17.35%), A*02:01 (11.58%); B*40:01 (15.67%), B*46:01 (11.87%), B*58:01 (9.05%); DRB1*09:01 (17.54%),DRB1*12:02 (9.64%) and DRB1*08:03 (8.65%). A total of 171 A‐B‐DRB1 haplotypes with a frequency of >0.1% were presented and the five most common haplotypes were A*33:03‐B*58:01‐ DRB1*03:01, A*02:07‐B*46:01‐DRB1*09:01, A*30:01‐B*13:02‐DRB1*07:01, A*33:03‐B*58:01‐RB1*13:02 and A*11:01‐B*15:02‐DRB1*12:02. The information will be useful for selecting unrelated bone marrow donors and for anthropology studies and pharmacogenomics analysis.     

Discovery of the novel HLA‐DRB1*09:01:08 allele in a Taiwanese volunteer bone marrow donor and identification of the probable HLA‐A,HLA‐B and HLA‐DRB1 haplotype in association with DRB1*09:01:08

We report here the novel variant of HLA‐DRB1*09:01, DRB1*09:01:08, discovered in a Taiwanese volunteer bone marrow donor by a sequence‐based typing (SBT) method. The DNA sequence of DRB1*09:01:08 is identical to the sequence of DRB1*09:01:02 in exon 2 except a silent mutation at nucleotide position 261(C→T) (GCC→GCT at codon 58). We hypothesize DRB1*09:01:08 was probably derived from DRB1*09:01:02 via a nucleotide point mutation event. The plausible HLA‐A, HLA‐B and HLA‐DRB1 haplotype in association with DRB1*09:01:08 was deduced as A*02:07‐B*46:01‐DRB1*09:01:08.     

A novel HLA‐B allele,B*58:01:12, detected in a Taiwanese volunteer bone marrow stem cell donor using sequence‐based typing method

Human leukocyte antigen‐B*58:01:12, a novel rare allele of HLA‐B*58:01 variant, was found in a Taiwanese volunteer bone marrow donor by SBT (sequence‐based typing) method. The DNA sequence of B*58:01:12 is identical to the sequence of B*58:01:01 in exons 2, 3 and 4 except at nucleotide position 483 where nucleotide C is substituted by T (at codon 137; GAC?GAT). Due to the silent point mutation, the amino acid sequence of B*58:01:12 is identical to the sequence of B*58:01:01. The HLA haplotype in association with B*58:01:12 may be deduced as A*33:03‐B*58:01:12‐DRB1*03:01. The discovery of B*58:01:12 adds further polymorphism of B*58:01 in Taiwanese population.     

Human leucocyte antigens class II allele and haplotype association with Type 1 Diabetes in Madeira Island (Portugal)

This study confirms for Madeira Island (Portugal) population the Type 1 Diabetes (T1D) susceptible and protective Human leucocyte antigens (HLA) markers previously reported in other populations and adds some local specificities. Among the strongest T1D HLA associations, stands out, as susceptible, the alleles DRB1*04:05 (OR = 7.3), DQB1*03:02 (OR = 6.1) and DQA1*03:03 (OR = 4.5), as well as the haplotypes DRB1*04:05‐DQA1*03:03‐DQB1*03:02 (OR = 100.9) and DRB1*04:04‐DQA1*03:01‐DQB1*03:02 (OR = 22.1), and DQB1*06:02 (OR = 0.07) and DRB1*15:01‐DQA1*01:02‐DQB1*06:02 (OR = 0.04) as protective. HLA‐DQA1 positive for Arginine at position 52 (Arg52) (OR = 15.2) and HLA‐DQB1 negative for Aspartic acid at the position 57 (Asp57) (OR = 9.0) alleles appear to be important genetic markers for T1D susceptibility, with higher odds ratio values than any single allele and than most of the haplotypes. Genotypes generated by the association of markers Arg52 DQA1 positive and Asp57 DQB1 negative increase T1D susceptibility much more than one would expected by a simple additive effect of those markers separately (OR = 26.9). This study also confirms an increased risk for DRB1*04/DRB1*03 heterozygote genotypes (OR = 16.8) and also a DRB1*04‐DQA1*03:01‐DQB1*03:02 haplotype susceptibility dependent on the DRB1*04 allele (DRB1*04:01, OR = 7.9; DRB1*04:02, OR = 3.2; DRB1*04:04, OR = 22.1).     

HLA class II susceptibility pattern for type 1 diabetes (T1D) in an Iranian population

This study aimed to determine the HLA‐DRB1/HLA‐DQB1 susceptibility and protection pattern for type 1 diabetes (T1D) in a population from Hamadan, north‐west of Iran. A total of 133 patients with T1D were tested for HLA‐DRB1 and HLA‐DQB1 alleles using PCR‐SSP compared to 100 ethnic‐matched healthy controls. Alleles and haplotypes frequencies were compared between both groups. The most susceptible alleles for disease were HLA‐DRB1*03:01, DRB1*04:02, DQB1*02:01 and DQB1*03:02, and protective alleles were HLA‐DRB1*07:01, *11:01, *13:01, *14:01 and DRB1*15 and HLA‐DQB1*06:01, *06:02 and *06:03. Haplotype analysis revealed that patients with T1D had higher frequencies of DRB1*03:01–DQB1*02:01 (OR = 4.86, P < 10^?7) and DRB1*04:02–DQB1*03:02 (OR = 9.93, P < 10^?7) and lower frequencies of DRB1*07:01–DQB1*02:01 (P = 0.0005), DRB1*11:01–DQB1*03:01 (P = 0.001), DRB1*13:01–DQB1*06:03 (P = 0.002) and DRB1*15–DQB1*06:01 (P = 0.001) haplotypes compared to healthy controls. Heterozygote combination of both susceptible haplotypes (DR3/DR4) confers the highest risk for T1D (RR = 18.80, P = 4 × 10^?5). Additionally, patients with homozygote diplotype, DR3/DR3 and DR4/DR4, showed a similar risk with less extent to heterozygote combination (P = 0.0004 and P = 0.01, respectively). Our findings not only confirm earlier reports from Iranians but also are in line with Caucasians and partly with Asians and some African patients with T1D. Remarkable differences were the identification of DRB1*04:01–DQB1*03:02, DRB1*07:01–DQB1*03:03 and DRB1*16–DQB1*05:02 as neutral and DRB1*13:01–DQB1*06:03 as the most protective haplotypes in this study.     

A novel HLA-B*40 sequence--B*40:92

A new allele, HLA‐B*40:92, was identified in a north‐western European subject during polymerase chain reaction using sequence‐specific priming (PCR‐SSP)‐based typing of haematopoietic stem cell (HSC) donors. B*40:92 differs from B*40:01:01 by six nucleotides at positions 559, 560, 603, 605, 610 and 618 in exon 3 which represents a substitution motif of at least 60 nucleotides. This motif, which occurs in numerous HLA alleles including the relatively high frequency B*15 and B*35 allele families, encode four amino acid changes at positions 163 (glutamic acid > leucine), 177 (aspartic acid > glutamic acid), 178 (lysine > threonine), 180 (glutamic acid > glutamine) and a silent substitution, conserved alanine, at codon 182. Thus, it is likely that HLA‐B*40:92 occurred following a gene conversion‐like or interallelic recombination event involving B*40:01:01 and probably a B*15 or more likely a B*35 family allele. HLA‐B*40:92 was found on a haplotype with HLA‐A*02:01, B*40:92, C*03:04, DRB1*13:02, DRB3*03:01, DQA1*01:02, DQB1*06:04, DPA1*02:02, DPB1*05:01. Tests on 69 selected B40 and B35 antisera and Lambda Monoclonal Trays? show that B*40:92 encodes a ‘short’ B40/B60 serological specificity which displays some HLA‐B35 reactivity. The HLA‐B40 and HLA‐B35 motifs (possible epitopes) responsible for this serological reactivity were identified. This single example of HLA‐ B*40:92 was found in 56,823 consecutive HLA PCR‐SSP typed HSC donors indicating a carriage frequency of 0.00176% (allele frequency 0.00001) in blood donors resident in Wales. An Epstein‐Barr virus transformed B‐cell line from the HLA‐B*40:92 donor is available.     

Allelic and haplotype diversity of HLA‐A,HLA‐B and HLA‐DRB1 gene at high resolution in the Nanning Han population

The distribution of human leucocyte antigen (HLA) allele and haplotype varied among different ethnic populations. In this study, we investigated the allele and haplotype frequencies of HLA‐A, HLA‐B and HLA‐DRB1 loci in the Nanning Han population who live in Guangxi province of China. We identified 26 HLA‐A, 56 HLA‐B and 31 HLA‐DRB1 alleles in 562 Nanning individuals of Han ethnic group by sequence‐based typing method. Of these, the three most common alleles in HLA‐A, HLA‐B and HLA‐DRB1 loci, respectively, were A*11:01 (32.12%), A*02:07 (12.54%), A*24:02 (12.01%); B*46:01 (14.41%), B*15:02 (13.61%), B*40:01 (11.48%); DRB1*15:01 (14.15%), DRB1*16:02 (11.57%) and DRB1*12:02 (10.14%). With the exception of HLA‐DRB1, the p values of the HLA‐A and HLA‐B loci showed that the HLA allelic distribution in this population was in accordance with Hardy–Weinberg expectation (p > 0.05). A total of 173 HLA~A‐B~DRB1 haplotype with a frequency of >0.1% were presented and the three most common haplotype were HLA‐A*33:03~B*58:01~DRB1*03:01 (6.12%), HLA‐A*11:01~B*15:02~DRB1*12:02 (3.39%) and HLA‐A*11:01~B*15:02~DRB1*15:01 (3.22%). The phylogenetic tree and the principal component analysis suggested that Nanning Han population had a relative close genetic relationship with Chinese Zhuang population and a relative distant genetic relationship with Northern Han Chinese. The information will be useful for anthropological studies, for HLA matching in transplantation and disease association studies in the Chinese population.     

Identification of the novel HLA‐B*13:02:13 allele in a Taiwanese haematopoietic stem cell donor and the probable HLA haplotype in association with B*13:02:13

Using sequence‐based typing method, we found a new HLA‐B*13:02 variant, B*13:02:13, in a Taiwanese haematopoietic stem cell donor. The DNA sequence of B*13:02:13 is identical to the sequence of B*13:02:01 in exons 2 and 3 except the nucleotide at position 588 where G is replaced by T (codon 172; CTG→CTT). The DNA sequence variation did not alter the amino acid sequence of B*13:02:01. The generation of B*13:02:13 is thought to derive from B*13:02:01 as a result of a silence mutation. The probable HLA‐A, HLA‐B and HLA‐DRB1 haplotype in association with B*13:02:1 may be deduced as HLA‐A*24‐B*13:02:13‐DRB1*07:01 or HLA‐A*02‐B*13:02:13‐DRB1*07:01. The discovery of B*13:02:13 furthers the polymorphism of HLA‐B*13 and HLA‐B*13:02.     

A single center study of protective and susceptible HLA alleles and haplotypes with end-stage renal disease in China

Chronic kidney disease (CKD) is becoming a global public health problem and usually cause End-Stage Renal Disease (ESRD) in the end of progression. To analyze the associations of HLA-A, -B, -C, -DRB1 and -DQB1 alleles at high resolution with ESRD in Jiangsu province of China, a total of 499 unrelated patients with ESRD from the First Affiliated Hospital with Nanjing Medical University and 1584 healthy controls from Jiangsu Branch of Chinese Marrow Donor Program (CMDP) were genotyped at HLA-A, -B, -C, -DRB1 and -DQB1 loci. Statistical analysis was applied to compare the differences of HLA allele frequencies between patients with ESRD and healthy controls. As results, no protective allele at A locus was found and the susceptible alleles were A*11:01 and A*31:01. At B locus, B*15:01, B*55:02 and B*39:05 emerged as susceptible alleles, whereas no protective allele was found. At C locus, C*06:02 and C*07:01 emerged as protective alleles and no susceptible allele was found. At DRB1 locus, six alleles including DRB1*03:01, DRB1*04:03, DRB1*04:04, DRB1*04:05, DRB1*11:01 and DRB1*12:02 emerged as susceptible alleles, while DRB1*15:01 emerged as a protective allele. At DQB1 locus, DQB1*02:01, DQB1*03:01, DQB1*03:02 and DQB1*04:01 emerged as susceptible alleles, while DQB1*06:02 and DQB1*06:09 emerged as protective alleles. Haplotype A*11:01-C*03:03-B*15:01-DRB1*11:01-DQB1*03:01 containing four susceptible alleles was regarded as the most susceptible haplotype. The susceptible alleles and haplotypes might be used as some important risk classification markers. Besides, in the consanguineous renal transplantation, it would be very beneficial for the long-term survival of renal transplant patients to avoid the susceptible alleles and haplotypes in selecting optimal donors.     

Discovery of the novel HLA‐DRB1*04:05:14 allele in a Taiwanese unrelated haematopoietic stem cell donor by a sequence‐based typing method

We report here a de novo HLA‐DRB1*04 allele, DRB1*04:05:14, discovered in a Taiwanese unrelated volunteer bone marrow stem cell donor by a sequence‐based typing method. In exon 2, the DNA sequence of DRB1*04:05:14 is identical to the sequence of DRB1*04:05:01 except the nucleotide at positions 321 where C is replaced by T (at codon 78; TAC→TAT). Due to the silent mutation, the nucleotide substitution produced no amino acid variation in comparison with DRB1*04:05:01. We assume DRB1*04:05:14 was derived from DRB1*04:05:01 via a point mutation. The probable HLA‐A, ‐B and ‐DRB1 haplotype in association with DRB1*04:05:14 may be deduced as A*11‐B*55‐DRB1*04:05:14. We here report the Taiwanese ethnicity of DRB1*04:05:14.     

Allele and haplotype frequencies of HLA‐A,B, C,DRB1 and DQB1 genes in polytransfused patients in ethnically diverse populations from Brazil

The red blood transfusion is a practice often used in patients with haematological and oncological diseases. However, the investigation of human leucocyte antigen (HLA) system frequency in these individuals is of great importance because multiple transfusions may lead to HLA alloimmunization. Brazil is a country that was colonized by many other ethnicities, leading to a mixed ethnicity and regionalized population. In view of the importance of HLA typing in these patients, the aim of this study was to investigate the allele and haplotype frequencies from polytransfused patients from three different regions from Brazil. HLA‐A, HLA‐B, HLA‐C, HLA‐DRB1 and HLA‐DQB1 genotyping of 366 patients was performed by PCR‐SSO, based on the Luminex technology (One Lambda^®), and the anti‐HLA class I and class II antibodies were analysed using LabScreen Single Antigen Antibody Detection (One Lambda, Inc.). Allele and haplotype frequencies of polytransfused patients of three regions from Brazil were obtained using the Arlequin program. The most frequent allele frequencies observed were HLA‐A*02, A*03, B*15, B*35, B*51, C*07, C*04, C*03, DRB1*13, DRB1*11, DRB1*07, DRB1*03, DRB1*01, DQB1*03, DQB1*02, DQB1*06 and DQB1*05. There were differences between the groups for allele variants HLA‐B*57 (between Group 1 and Group 2) and HLA‐C*12 (between Group 1 and Group 3). The most frequent haplotypes found in the sample were HLA‐A*01B*08DRB1*03, DRBI*07DQB1*02, DRB1*01DQB1*05, DRB1*13DQB1*06 and A*02B*35. HLA class I and II antibodies were detected in 77.9% and 63.9% patients, respectively, while the both alloantibodies were detected in 62 (50.9%) patients. In conclusion, the HLA typing for polytransfused patients in each region has a great importance, as seen in this study; individuals from different regions from Brazil have HLA distribution not completely homogeneous.     

Recognition of HLA‐A*24:137 allele in a Taiwanese unrelated bone marrow stem cell donor and the plausible HLA haplotype associated with A*24:137

We detected a rare HLA‐A*24:137 allele in an unrelated Taiwanese haematopoietic stem cell donor during a routine SBT (sequence‐based typing) HLA typing exercise. The DNA sequence of A*24:137 is identical to the sequence of A*24:02:01:01 in exons 2 and 3 except at codon 21 where CGC was replaced with CAA. The DNA variation caused an amino acid alteration at amino acid residue 21 (R‐>Q). The HLA haplotype in association with A*24:137 may be deduced as A*24:137‐B*15‐DRB1*14. The formation of A*24:137 was probably the result of a nucleotide point mutation involving A*24:02:01:01. It remains to be determined whether A*24:137 is restricted to Taiwanese/Chinese ethnicity.