Identification of a novel HLA-C*07:02:25 allele by polymerase chain reaction sequence-based typing in a Chinese leukemia patient

Nucleotide sequence of HLA-C*07:02:25 allele was different from that of HLA-C*07:02:01:01 by a single nucleotide substitution at position 78C>G.     

HLA-A*02:07:02, a new allele identified by sequence-based typing in a Korean individual

The new allele A*02:07:02 shows a single nucleotide substitution compared with A*02:07:01 at codon 233 (ACC → ACT) without any amino acid change.     

Characterization of a new HLA‐A allele,HLA‐A*02:07:08, by cloning and sequencing

In this report, we present a novel HLA‐A*02:07 allele, HLA‐A*02:07:08. HLA‐A*02:07:08 was identified in an individual of Han ethnicity in Hunan province, southern China. Following polymerase chain reaction‐sequence‐based typing (PCR‐SBT), this new allele was further confirmed by cloning and sequencing. HLA‐A*02:07:08 differs from HLA‐A*02:07:01 by a single synonymous C to T substitution at nucleotide position 131 in exon 3.     

Characterization of the novel HLA-C*16:07:02 allele in a family of Benin origin

The novel allele HLA-C*16:07:02 differs from HLA-C* 16:07:01 by a silent nucleotide substitution at codon 220 (TAC → TAT).     

HLA‐A locus allelic dropout in Sanger sequence‐based typing due to the single nucleotide polymorphism of exon 1

The DNA‐based method is used widely for HLA genotyping in routine work, but some allele may be dropout in the genotyping procedure. Here, we reported a case with HLA‐A allele dropout in the Sanger PCR‐SBT test. The initial PCR‐SBT method with a commercial agent kit was not characterized, and the result of Luminex technology indicated the dropout as a HLA‐A*02 allele. Subsequently, the sequences of exons 2–4 were fully matched with the A*02:07 and A*11:01:01 by allele group‐specific primer amplification PCR‐SBT. On further analysis, a novel allele A*02:07:07 was identified, which has one nucleotide difference from A*02:07:01 at position 6 C>G of exon 1. According to the sequencing for 5′‐UTR to 3′‐UTR, the novel single nucleotide polymorphism of exon 1 was contributed to HLA‐A locus allele dropout in the sample. Our results indicated multiplatform analysis is necessary when a conclusive HLA type cannot be determined by a single methodology.     

Characterization of the novel HLA-C*07:195 allele in an Italian hematopoietic stem cell volunteer donor, detected by sequence-based typing

The new allele shows one nucleotide change from C*07:02:01:01 at 351 nt from C to A, resulting in an amino acid change at codon 93 of exon 3 from H to Q.     

A new MICA allele,MICA*007:07, characterized by cloning and sequencing

A new MICA allelic variant, MICA*007:07, was identified in an individual of Mongol ethnicity in the Inner Mongolia Autonomous Region, northern China. Following polymerase chain reaction‐sequence‐based typing (PCR‐SBT), this new allele was further confirmed by cloning and sequencing. MICA*007:07 differs from MICA*007:01 by a synonymous mutation from G to A at the 2nd nucleotide position in exon 2. MICA*007:07 was linked to HLA‐B*27:05.     

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 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.     

Sequence-based HLA high-resolution typing of a bone marrow donor/recipient pair reveals the novel HLA allele HLA-C*07:208

Nucleotide sequence of HLA-C*07:208 allele was different from that of HLA-C*07:02:01:01 by a single-nucleotide substitution at position 475 G>C.     

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.     

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.     

Characterization of three novel HLA-DRB1 alleles, DRB1*03:55, *11:46:02 and *04:92, by exon 2, 3 and 4 sequencing-based typing

Sequencing-based typing of HLA-DRB1 gene, allowed us to characterize three new alleles. DRB1*03:55 shows one nucleotide change regarding DRB1*03:01:01G, resulting in an amino acid replacement at position 80 R > I. DRB1*11:46:02 presents one synonymous nucleotide change at codon 34 (CAG > CAA) with regard to DRB1*11:46:01. Finally, DRB1*04:92 has one nucleotide change from DRB1*04:07:01 at codon 207 in exon 4, producing an amino acid replacement (V > M) in the transmembrane domain.     

The new HLA-C allele C*07:170 shows a new polymorphism at amino acid position 147

The new HLA-C allele C*07:170 differs from C*07:01:01 by two nucleotides at exon 3.     

Identification of a novel HLA-B*46 allele, B*46:01:07, in a Chinese individual

The novel allele B*46:01:07 was identified in a Chinese individual by sequence-based typing.     

Identification of a new HLA-A*02 allele, HLA-A*02:305 N, which differs from the HLA-A*02:01:01 allele by a single nucleotide deletion in exon 4

The HLA-A*02:305N new allele lacks a nucleotide in exon 4 compared to HLA-A*02:01:01 allele.     

Identification of a novel HLA-B allele, B*35:01:25, by sequence-based typing in a Korean individual

The new allele B*35:01:25 showed a single nucleotide substitution compared with B*35:01:01 at codon 238 (GAT/GAC).     

Identification of a novel HLA-C*01 variant allele, C*01:46

A novel HLA-C*01 variant allele differs from the closest allele C*01:02:01 by single nucleotide change at coding sequence nt 316 C>T (codon 82 CGC>TGC) in exon 2, which causes an amino acid change Arg82Cys.     

A novel HLA-B*40 allele, HLA-B*40:74, detected in a Chinese individual

The HLA-B*40:74 allele has two nucleotide changes at positions 103 and 106 of exon 2 from the closest matching allele HLA-B*40:01:01.     

Two novel alleles at HLA‐B locus identified in two volunteer bone marrow donors by sequence‐based typing

Two novel human leucocyte antigen (HLA) class I alleles have been identified in two Italian individuals. HLA‐B*27:07:02 is identical to HLA‐B*27:07:01 except for a nucleotide substitution at position 846 (A‐>G) resulting in a silent mutation. HLA‐B*35:206 differs from the most similar allele, HLA‐B*35:08:01, because of a single base mutation at position 149 (G‐>C) causing an aminoacidic change at codon 26 from Gly to Ala.