Oriental HLA-A*11:90 detected in a Taiwanese cord blood sample and the haplotype in association with A*11:90 allele

We report here an HLA-A allele, A*11:90, found in a Taiwanese cord blood sample using DNA sequence-based typing (SBT) protocol after observing an anomalous reaction pattern in a sequence-specific oligonucleotide (SSO) typing exercise. The sequence of A*11:90 is identical to A*11:01:01, the most predominant A*11 variant in Taiwanese, in exon 2 but differs from A*11:01:01 in exon 3 by two nucleotide substitutions at codon 163 (c.487C>G and c.488G>A), resulting R163E. In comparison with the sequence of A*11:02:01, the second most predominant subtype of A*11 in Taiwanese A*11:90 has one nucleotide difference at codon 19 (c.55A>G) in exon 2 resulting K19E and two nucleotides variations at codon 163 (c.487C>G and c.488G>A) in exon 3 resulting R163E. HLA-A*11:90-B*40:02-DRB1*11:01 is the deduced probable HLA haplotype in association with A*11:90. The generation of A*11:90 is thought to involve a DNA recombination event between alleles A*11:01:01 and A*80:01 where A*80:01 donated a fragment of the DNA sequence (from n.t. 487 to n.t. 497) to the recipient sequence of A*11:01:01.     

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.     

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.     

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.     

Identification of two novel HLA-A*02 variants, A*02:319 and A*02:01:64, in two Taiwanese marrow stem cell donors by sequence-based typing

We report here two novel variants of HLA-A*02 allele, A*02:319 and A*02:01:64, discovered in two Taiwanese unrelated volunteer bone marrow donors by sequence-based typing (SBT) method. The DNA sequence of A*02:319 is identical to A*02:07 in exons 2 and 3 but varies with one nucleotide at codon 9 (TTC->TCC). The variation caused one amino acid substitution at residue 9 (F->S). On the other hand, the DNA sequence of A*02:01:64 is identical to the sequence of A*02:01:01:01 in exons 2 and 3 except a silent mutation at codon 114 (CAC->CAT). The probable HLA-A, HLA-B and HLA-DRB1 haplotypes in association with A*02:319 and A*02:01:64 were deduced as A*02:319-B*46:01-DRB1*04 and A*02:01:64-B*38:02-DRB1*16:02, respectively.     

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.     

Detection of two HLA-A alleles, A*31:30 and A*26:20, in two Taiwanese volunteer bone marrow donors by sequence-based typing

We here report detection of a novel sequence of HLA-A*31:30 and a confirmatory sequence of HLA*26:20 from two Taiwanese individuals. The sequence of A*31:30 is identical to that of A*31:01:02 in exons 2 and 3, except one nucleotide (n.t.) substitution c.539T > G resulting in p.Leu180Trp. The sequence of A*26:20 is identical to A*26:01:01 in exons 2 and 3, except a segment of the sequence from n.t. 78 to n.t.102. The mismatched sequence segment is identical to a sequence segment of A*02:03:01, suggesting that the formation of A*26:20 was resulted from a DNA recombination event between A*26:01:01 and A*02:03:01 sequences. A*26:20 differs from A*26:01:01 with c.98A > T resulting in p.Tyr33Phe.     

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 conserved HLA‐A*02:28 associated HLA haplotype,A*02:28‐B*15:11‐DRB1*09:01, restricted to Taiwanese

HLA‐A*02:28, found in a Korean and a Japanese, was reported independently to the IMGT/HLA database in 2003 and 2005, respectively. We report here eight Taiwanese unrelated bone marrow hematopoietic stem cell donors carrying A*02:28 detected during our routine HLA typing exercise. The probable HLA‐A, ‐B and ‐DRB1 haplotype in association with A*02:28 may be deduced from the eight marrow stem cell donor as A*02:28‐B*15:11‐DRB1*09:01. Our result suggests A*02:28‐B*15:11‐DRB1*09:01 is a conserved HLA haplotype restricted to Taiwanese.     

Detection of the rare HLA‐B*40:97 allele in an unrelated Taiwanese bone marrow donor

We detected a rare HLA‐B locus allele, B*40:97, in a Taiwanese unrelated donor in our routine HLA SBT (sequence‐based typing) exercise for a possible hematopoietic stem cell donation. In exons 2, 3 and 4, the sequence of B*40:97 is identical to the sequence of B*40:02:01 except one nucleotide at nucleotide position 760 (C‐>T) in exon 4. The nucleotide variation caused one amino acid alteration at residue 230 (L‐>F). B*40:97 was probably derived from a nucleotide substitution event where C was replaced by T at nucleotide 760 involving B*40:02:01. The HLA‐A, HLA‐B, HLA‐C, HLA‐DRB1 and HLA‐DQB1 haplotype in association with B*40:97 may be deduced as A*26:01‐B*40:97‐C*03:03‐DRB1*11:01‐DQB1*03:03. Our recognition of B*40:97 in Taiwanese helps to fill the void of ethnic information for the allele B*40:97 reported to the IMGT/HLA Database.     

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.     

Characterization of a novel HLA‐B*40 allele,HLA‐B*40:186:02, by cloning and sequencing

A novel HLA‐B*40 variant, HLA‐B*40:186:02, has been identified by cloning and sequencing in a southern Chinese Han population. Aligned with HLA‐B*40:01:01, HLA‐B*40:186:02 has a nonsynonymous cytosine mutation at nucleotide position 165 in exon 2, leading to amino acid change from glycine to arginine at codon 56. It differs from HLA‐B*40:186:01 by a synonymous change (adenine to cytosine) at position 165 in exon 2.     

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.     

A novel HLA‐B*14 allele – B*14:53 – genetics and serology

HLA‐B*14:53 was found in a UK European normal blood donor prior to registration on the Welsh Bone Marrow Donor Registry. It differs from B*14:13 by one base (103G>T) in exon 2 resulting in a substitution of alanine (A) in B*14:13 to serine (S) in B*14:53. Unique among current HLA‐B*14 alleles, B*14:53 and B*14:13 share a motif of 59 bases between positions 361 and 419 in exon 3. This motif is present in numerous HLA‐B alleles the commonest overall being B*08:01, suggesting that both B*14:53 and B*14:13 arose from intralocus gene conversion events with B*08:01. Thus, B*14:53 probably arose from B*14:01:01 (which has TCC at codon 11 (S), while B*14:13 arose from B*14:02:01:01 which has GCC at codon 11 (A). Additionally, the two likely B*14:53‐bearing and B*14:13‐bearing haplotypes are typical of B*14:01:01‐bearing and B*14:02:01:01‐bearing haplotypes, respectively. Serological testing, using 49 antisera with HLA‐B64, or B64, B65 reactivity, showed that the B*14:53 specificity did not react as a B64 (B*14:01) specificity and may appear as a short/weak HLA‐B14. This implies that residues additional to S at position 11 are involved in HLA‐B64 serological identity; for example, the motif 11S 97W 116F is possessed by B*14:01 and many other B*14 products (and B*39:79 plus some HLA‐C products) but not B65 (B*14:02) or the B*14:53 specificity. B*14:53 was found in a random HLA sequence‐based typed population of 32 530 normal subjects indicating a low precision allele frequency of 0.000015 in subjects resident in Wales.     

A novel allele, HLA-A*11:01:10, identified by sequence-based typing in a Chinese individual

The novel allele human leukocyte antigen (HLA)-A*11:01: 10 differs from HLA-A*11:01:10 by a synonymous nucleotide exchange at codon 146 in exon 2 (G/A). Here, we describe the identification of the novel allele HLA-A*11:01:10, which has been detected in a registered donor of the China Marrow Donor Program. The complete HLA typing results were as follows: A*02:01, *11:01:10; B*15:11, *15:18; C*03:03, *08:01; DRB1*08:02, *15:01.     

Characterization of a novel allelic variant in HLA‐B*40 lineage,HLA‐B*40:298:02, by cloning and sequencing

A novel allelic variant in HLA‐B*40 lineage, HLA‐B*40:298:02, has been identified in an individual of Han ethnicity afflicted with nasopharyngeal carcinoma in Hunan province, southern China. Following polymerase chain reaction–Sanger sequence‐based typing (PCR–SBT), this new variant was further confirmed by two distinct strategies of cloning and sequencing. HLA‐B*40:298:02 differs from HLA‐B*40:298:01 by a single synonymous cytosine substitution at nucleotide position 26 (T→C) in exon 3, which corresponds to codon 99 of the mature HLA‐B mRNA molecule. This new allele has an estimated frequency of 0.0002, in about 2,500 sequence‐based typed subjects from the same population.     

Identification of a novel HLA-A allele, A*11:60, in a Taiwanese family

We report the identification and sequence analysis of a new HLA-A11* variant, A*11:60 allele, found in a Taiwanese leukaemic patient and his siblings. The novel A*11 variant is identical to A*11:03 in exon 2 but differs from A*11:03 in exon 3 by one nucleotide substitution at position 527 (A→T) causing an amino acid change at codon 152 E (Glu)→V (Val) (GAG→GTG). In comparison with HLA-A*11:01:01, allele A*11:60 has two nucleotide differences in exon 3: at nt 524 (A→G) (CAT→CGT) and at nt 527 (C→T) (GCG→GTG) leading to two amino acid variations at residues 151 H (His)→R (Arg) and 152 A (Ala)→V (Val).     

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.     

Identification of a novel HLA‐A allele,A*1131, in a Taiwanese

Here we report the identification and sequence analysis of a new HLA‐A11* variant, A*1131 allele, found in a Taiwanese volunteer bone marrow donor. The novel A*11 variant is identical to A*1125 in exon 2 but differs from A*1125 in exon 3 by one nucleotide substitution at position 527 causing an amino acid change at codon 152 E→V (GAG→GTG). In comparison with HLA‐A*110101, allele A*1131 has three nucleotide differences in exon 3: 527 C→T, 538 C→T and 539 A→T leading to two amino acid variations at residues 152 A→V and 156 Q→L.     

Detection of two HLA-B*27 alleles, B*27:25 and B*27:86, in two Taiwanese blood donors by sequence-based typing

We report here two HLA-B*27 alleles, B*27:86 and B*27:25, found in two Taiwanese blood donors. The new sequence of B*27:86 is identical to B*27:04:01 in exons 2 and 3, except at nucleotide 602 (A → G) in exon 3. The nucleotide change caused an amino acid substitution from E to G at amino acid residue 177. The sequence of B*27:25 is identical to B*27:04:01 in exons 2, 3, 4, 5, 6 and 7 except at nucleotides 538, 539, 559 and 560 in exon 4. The nucleotide changes caused amino acid substitutions from L to W and from E to L at residues 156 and 163, respectively. The generation of B*27:86 was probably resulted by a point mutation while the generation of B*27:25 may have been derived from a sequence recombination event between B*46:01:01 and B*27:04:01. The probable HLA-A, -B and -DRB1 haplotypes in association with B*27:86 and B*27:25 may be deduced as A*11:53-B*27:86-DRB1*12 and A*11:01-B*27:25-DRB1*04:05, respectively.