Twenty-three novel alleles increase diversity at the HLA-C locus

HLA-B*15:33, a rare allele whose product reacts as an HLA-B62 and -Cw5/Cw8 specificity

Using PCR with sequence-specific primers (SSP) and subsequent sequencing of exons 2 and 3, we identified an example of B*15:33 in a likely north-western European Caucasoid volunteer haemopoietic stem cell (HSC) donor. This was only the second example submitted to the IMGT/HLA database since B*15:33 was first described in 1996. B*15:33 differs from B*15:01:01:01 by three nucleotides resulting in two amino acid differences with B*15:01 (131S>R, 138T>K). This allele encodes a typical HLA-B62 specificity--as confirmed using 17 local antisera from parous women and 19 monoclonal antibodies directed towards B15, B62 and B63 specificities. Importantly, it also reacted as a Cw5/Cw8 specificity when tested against 21 Cw5, Cw5/Cw8 and Cw8 antisera. This Cw5/Cw8 reactivity is probably due to the B*15:33 specificity having lysine at position 138 which is possessed by numerous C*05 and many C*08 products. B*15:33 is likely to have derived from a HLA-B/C inter-locus gene conversion event. HLA-B*15:33 is clearly rare--this single example was found during the HLA PCR-SSP-based typing of 57,079 potential HSC donors. This indicates an allele frequency of <0.00001 in blood donors resident in Wales. An Epstein-Barr virus transformed B-cell line from the HLA-B*15:33 donor is available.

Increased HLA class I and II diversity as 72 novel alleles are identified in volunteers for the National Marrow Donor Program Registry in 2010

Seventy-two novel human leukocyte antigen (HLA) class I and class II alleles are described from volunteers for the 'Be The Match Registry®': 17 HLA-A alleles, 12 HLA-C alleles, 31 HLA-B alleles and 12 HLA-DRB1 alleles. Forty-six (≈ 64%) of the 72 novel alleles are single-nucleotide substitution variants when compared with their most homologous allele. Five of these single-nucleotide variants are silent substitutions and one creates a non-expressed allele (B*44:108N). The remaining novel alleles differ from their most similar allele by two to five nucleotide substitutions. One of the novel HLA-C alleles (C*07:150Q) is of questionable expression due to an insertion of 21 nucleotides starting at codon 143 that adds seven amino acids to exon 3. An inter-locus gene conversion may have created the novel allele HLA-A*23:31 that shares its codon differences with HLA-B*07:28. Some of the new alleles encode novel codons and unique amino acid changes at polymorphic positions in the HLA-A (codons 116 and 150), HLA-C (codon 114), HLA-B (codons 11, 21, 35, 42, 48, 73, 98 and 170) and HLA-DRB1 (codon 29) loci.

A novel HLA-C*01 variant allele, HLA-C*01:38

The novel HLA-C*01:38 variant allele differs from the closest allele C*01:02:01 by a single nucleotide change at coding sequence (CDS) nt 430 G>A (codon 120 GGC>AGC) in exon 3, which causes an amino acid change Gly120Ser.

Characterization of a novel HLA-Cw*07 variant allele, Cw*075602

The novel human leukocyte antigen (HLA)-Cw*075602 variant allele differs from the closest allele Cw*07020101 by a single nucleotide change at genomic DNA nt 473 G > C (CDS nt 343 G > C , codon 91 GGG > CGG ) in exon 2, which results in an amino acid change Gly91Arg.

Cloning and sequencing analysis of a novel HLA-Cw*08 variant allele, Cw*0827

The novel HLA-Cw*0827 variant allele differs from the closest allele Cw*0802 by five nucleotide changes.

Identification of a novel HLA-C allele, Cw*021602, by sequence-based typing in a family of German descent

The novel allele HLA-Cw*021602 differs from HLA-Cw*021601 by a nuecleotide substitution at condon 162 (ACG to ACA).

A novel HLA-Cw*01 variant allele, HLA-Cw*0130

The novel HLA-Cw*0130 variant allele differs from the closest allele Cw*010201 by single nucleotide change at genomic nt 959 T>C (CDS nt 583 T>C, codon 171 TAC>CAC) in exon 3, which causes an amino acid change Tyr171His.

Description of novel class I alleles encountered during routine registry typing in 2007

Twenty-six novel human leukocyte antigen (HLA) class I alleles are described: 3 HLA-A alleles, 19 HLA-B alleles and 4 HLA-C alleles. Only one of the novel alleles (HLA-B*0753) was found in multiple individuals and likely is not uncommon in the population. Nineteen (approximately 70%) of the 26 novel alleles are single nucleotide substitution variants when compared with their most homologous allele. Four of these single nucleotide variants are silent substitutions, and one creates a null allele. The remaining novel alleles differ from their most similar allele by two to six nucleotide substitutions. Some of the new alleles encode novel codons and unique amino acid changes at polymorphic positions in the HLA-B lows (codons 30, 67 and 72), while HLA-Cw*0347 encodes an amino acid change at a position not previously reported to be polymorphic for this locus.