Novel HLA-DRB1 alleles discovered during routine sequencing based typing,DRB1*03052, DRB1*04032, DRB1*1139 and DRB1*1346

We report the discovery of four HLA-DRB1 alleles during routine sequencing based typing (SBT). These alleles--DRB1*03052, DRB1*04032, DRB1*1139 and DRB1*1346--differ from previously identified DRB1 alleles by known nucleotide polymorphisms.     

Identification of novel DRBI*13 (DRB1*1333), DRB1*04(DRB1*0426) and DRB5* (DRB5*0109) alleles

Abstract: Three novel HLA class H alleles (DRB1*1333, DRB1*O426, DRB5*0109) are described here. The 3 novel alleles were initially detected as previously unidentified SSO hybridization patterns using the CANTYPE reverse hybridization assay. Sequences were determined by cloning/sequencing. DRB1*1333 is identical to DRB1*1303 except for a single nucleotide substitution (ACC→AAC), changing codon 77 from Thr to Asn. This polymorphism is typical for DRB1*03 alleles. DRB1*0426 is identical to DRB1*0401 except for a single nucleotide substitution (GCC→ACC) at codon 58, changing the encoded Ala to Thr. DRB5*0109 is identical to DRB5*0101, except for a single nucleotide substitution (GAC→AAC), changing codon 70 from Asp to Asn. Both latter polymorphisms were so far undetected in DRB alleles. DRB1*1333 could have arisen from a gene conversion event, but DRB1*0426 and DRB5*0109 most likely were generated by point mutation events. For all 3 alleles, the sequence was confirmed by the original hybridization pattern (DRB1*1333) or by hybridization to a newly designed probe (DRB1*0426 and DRB5*0109). Ethnic backgrounds were Lebanese for DRB1*1333 and Caucasian for DRB1*0426 and DRB5*0109.     

Identification of new DRB1*07 (DRBl*0703), DRB1*08 (DRB1*0817) and two DRB3* (DRB3*0302 and DRB3* 01014) alleles

Abstract: We report here the identification of four novel DRB alleles using a reverse hybridization (CANTYPE) assay. Molecular cloning and sequencing confirmed the initial unusual hybridization patterns. All four new alleles were detected during routine HLA typing for the Canadian Unrelated Bone Marrow Donor Registry. DRBl*0703 is identical to DRB1*0701 except for a single nudeotide substitution (AGA→AGT), changing codon 29 from Arg to Ser, a so far undetected DRB polymorphism. DRB1*0817 differs from DRBl*0801 by a single nucleotide substitution (TAC→TTC), changing codon 47 from Tyr to Phe. This polymorphism has not, until now, been identified in DRB1*08 alleles. Compared with DRB3*0301, DRB3*0302 contains a single nucleotide substitution (TAC→CAC) at codon 30, changing the encoded Tyr to His. This polymorphism is typical for DRB3*02 alleles. DRB3*01014 is identical to DRB3*0101 except for a single silent nucleotide substitution (GGG→GGA) at codon 84. This polymorphism has previously only been described for the DRB1*15012 allele. DRB1*0817, DRB3*0302 and DRB3*01014 may have arisen from gene conversion, but DRB1*0703 most likely was generated by a point mutation event. The DRB3*0302 allele was detected in two unrelated subjects, while the other three have each only been detected once.     

Identification of two new HLA-DRB1 alleles,DRB1*1138 and DRB1*1344

Two new HLA-DRB1 alleles have been identified by sequencing based typing (SBT). HLA-DRB1*1138 and DRB1*1344 were discovered after following up ambiguous results involving unusual alleles after DRB1 generic typing.     

Identification of three new DRB1 alleles,DRB1*0107, *0425 and *13012 and confirmation of DRB4*01033

The characterization of three novel DRB1 alleles is described, DRB1*0107, DRB1*0425 and DRB1*13012 as well as confirmation of DRB4*01033. Two alleles, DRB1*0107 and *0425, showed amino acid differences with previously identified HLA molecules. In DRB1*0107, the glutamine at position 10 was substituted by a glutamic acid. DRB1*0425 showed one amino acid difference with DRB1*0418 (I to F) at position 67, and five amino acid differences with DRB1*04011 at positions 67 (L to F), 70 (Q to D), 71 (K to R), 74 (A to L) and 86 (G to V). The alleles DRB1*13012 and DRB4*01033 had protein sequences identical to DRB1*13011 and DRB4*01031/01032, respectively. Nucleotide differences were present at position 306 for DRB1*13012 and at position 321 for DRB4*01033.     

Identification of three novel alleles: DRB3*0110, DRB1*1140, and DRB1*140102

Three novel human leukocyte antigen class II alleles (DRB3*0110, DRB1*1140, and DRB1*140102) are described here. The three novel alleles were initially detected as previously unidentified SSO hybridization patterns using CANTYPE((R)) reverse hybridization assay. Sequences were determined by cloning/sequencing. DRB3*0110 allele is identical to DRB3*010101, except for a single nucleotide substitution (CGC-->AGC) changing codon 39 from Arg to Ser. This polymorphism has not, until now, been identified in DRB allele. Thus, this is an unusual mutation as the codon 39 is a fairly conserved region. The new DRB1*1140 is identical to DRB1*1116, except for a single nucleotide substitution at codon 67 from ATC (encoding for isoleucine) to TTC (encoding for phenylalanine). This polymorphism is commonly found in DRB1*11 alleles. Compared with DRB1*140101, DRB1*140102 contains a single silent nucleotide substitution (TAT-->TAC, both encoding for tyrosine) at codon 78. This polymorphism is commonly found in DRB1*14 alleles. The three new DRB alleles may have been generated by a point mutation event. The DRB3*0110 and DRB1*140102 were identified in Caucasoid individuals. The ethnic origin of the subject carrying the DRB1*1140 allele is Egyptian. The DRB1*140102 was detected in two unrelated individuals; the DRB3*0110 and DRB1*1140 were only identified once, in a total population of 80,000.     

Report of a new DRB1*13 allele: DRB1*1336

This brief communication describes the characterization of a new allele, DRB1*1336.     

Novel HLA-DRB1 alleles revealed by sequencing based typing,DRB1*04053 and DRB1*1143

We report the discovery of two HLA-DRB1 alleles by sequencing based typing (SBT). DRB1*04053 differs from previously reported DRB1 alleles by a single synonymous nucleotide substitution, resulting in a unique polymorphism at codon 93. DRB1*1143 differs from previously identified DRB1 alleles by a single non-synonymous nucleotide substitution, resulting in a polymorphism observed in other DRB1 and DRB3 alleles1.     

Identification of a novel DRB1 allele, DRB1*1112, by sequence-based DRB typing

We report here a novel DRB1 allele (DRB1*1112) identified during sequence-based HLA-DRB typing. Polymerase chain reaction with generic DRB primers and group-specific primers and subsequent sequencing yielded identical results. Molecular cloning and sequencing confirmed that the new DRB1 allele is identical to DRB1*11011 and 1129 at exon 2 except for a single nucleotide substitution at codon 37, changing the codon from Tyr (DRB1*11011) or Ser (DRB1*1129) to Phe.     

An unusual DRB1*1503 haplotype without a detectable DRB5 locus in a black African family

A DRB1*1503 allele not associated with DRB5 locus has been detected in an African family during routine HLA typing for bone marrow transplantation. PCR/SSOP analysis showed the DR2-associated alleles in all the family members but the DRB5 locus appeared to be absent in the patient and his brother. The samples were then analyzed for the presence of DRB6 pseudogenes and we found that the unusual haplotype was associated with DRB6*0101 allele. This finding strengthen the hypothesis of a recombination hot spot between DRB1 and DRB6 genes.     

A novel HLA-DRB1 sequence, DRB1*11272

We describe the complete exon 2 sequence of a novel HLA-DRB1 allele, DRB1*11272. This allele differs from the DRB1*11271 allele by a synonymous mutation in codon 77 where an AAT is replaced with AAC, both encode for the amino acid asparagine. The same motif at codon 77 has also been found in DRB1*1107, DRB1*1333, DRB1*0422 and in most DRB1*03 alleles. A partial exon 2 sequence of this allele has previously been deposited in the EMBL Sequence Database under the accession number AF186407.     

Identification of a novel DRB1-allele (DRB1*0106) by sequence-based typing

We report herein the identification of a new DRB1 allele using sequence-based typing. The new allele, DRB1*0106, was detected during routine HLA typing of a patient undergoing bone marrow transplantation. DRB1*0106 is identical to DRB1*0101 except for two codons, 71 (AGG-->GCG) and 86 (GGT-->GTG), changing the encoded arginine to alanine and glycine to valine. Both sequences were confirmed by polymerase chain reaction with sequence-specific primers (PCR-SSP). The polymorphism at codon 71 has not been, until now, identified in DRB1*01 alleles, although it is present in all the DRB1*15 alleles as well as DRB1*1309 and DRB1*1424.     

Description of a novel HLA-DRB1 allele,DRB1*1207

A new DRB1 allele has been identified during routine HLA-DRB1 generic typing with sequence specific oligonucleotides. The new allele was confirmed by PCR-restriction fragment length polymorphism analysis and subsequently sequenced. This showed the novel allele, named HLA-DRB1*1207, was similar in sequence to DRB1*12011, except for codon 69 of exon 2.     

Identification of a novel DRB1*04 allele: DRB1*0445

The novel allele DRB1*0445 differs from DRB1*04051 by a single nucleotide substitution at codon 23 (CGG-->CCG), resulting in an amino-acid change from arginine to proline. The haplotype associated with the novel allele is A*2402-B*5401-Cw*0102-DRB1*0445-DRB4*01-DQB1*0302.