A novel HLA-C allele, Cw*0617 I. Fae ´, A. Rosenmayr, W. R. Mayr & G. F. Fischer Department of Blood Group Serology, Medical University of Vienna, Vienna, Austria Key words: HLA-Cw*0617; HLA-C; allele Sequencing analysis of exons 1–3 of the human leukocyte antigen (HLA)-C gene showed a novel allele, HLA- Cw*0617. While the amino acid sequence is identical with the HLA-Cw*060201 allele, the leader peptide differs in three amino acids. Typing of human leukocyte antigen (HLA)-C alleles in an unrelated bone marrow donor from the Weinviertel in Lower Austria, led to inconclusive results: after preparation of genomic DNA using a commercial extraction method (GenoM6; Genovision, Vienna, Austria), reverse-phase sequence specific oligonucleotide probes (SSO) typing as performed with a commercial kit (DynalReli SSO HLA-Cw Test; Dynal Biotech, Bloomsborough, UK) suggested an HLA-Cw*02, *06 genotype; a probe detecting the ‘EPRAPW’ motif at AA position 41, however, missed. The same HLA-C genotype was indicated by sequence specific primers (SSP) typing (Olerup SSP HLA-C low resolution; Genovision); but, again, a primer pair including an oligonucleotide that detects an adenosine at nucleotide position 28 did not show the expected positive reaction. Cycle sequencing analysis with fluorescently labelled dideoxynucleotides (Big Dye Terminator Cycle Sequencing kit; ABI, Foster City, CA) on an ABI 3100 capillary sequencer was performed by directly sequencing PCR products that included either exons 1 and 2 (amplification and sequencing primers: CL1-14amp-C1, 5 0 -CCG AGG ATG CGG GTC ATG GC-3 0 and, CL1-320G rev 5 0 -CCT CGC TCT GGT TGT AGT AGC-3 0 ) or exons 2 and 3 (amplification and sequencing primers: 5CIn1-61: 5 0 -AGC GAG GGK CCC GCC CGG CGA-3 0 and 3CIn3-12: 5 0 - GGA GAT GGG GAA GGC TCC CCA CT-3 0 ) of the HLA-C gene. Because of the heterozygous genotype, the resulting sequence could not unambiguously be assigned to alleles. Therefore, haplotype-specific isolation of genomic DNA was performed, using the Haplotype-specific Extrac- tion Kit (Genovision) with the HLA-C specific probes ‘Cw142G’ and ‘Cw97G’ according to the manufacturer’s instructions. The DNA was then amplified in the same way as performed for the regularly prepared DNA and the amplification products again were directly sequenced. The sequencing results suggested a HLA-Cw*020202 and a novel allele, HLA-Cw*0617. The reaction patterns of SSP and SSO tests are in accordance with the sequencing results. Regarding exons 2 and 3, the HLA-Cw*0617 allele differs from the 060201 allele by a synonymous nucleotide exchange at codon 47 (Figure 1). Therefore, the predicted peptide-binding groove is the same between those two alleles. However, exon 1 of the HLA-Cw*0617 allele differs in three nucleotides (codons 29, 215 and 217, Figure 1) from the HLA-Cw*060201 allele. It is identical with the exon 1 of other HLA-C alleles including the HLA- Cw*07020101 allele, however. Therefore, it seems more likely that the generation of the new allele has occurred by a recombination event within exon 2, between a Cw*060201 and another, e.g. Cw*070201 allele than by a series of nucleotide substitutions. A family study was undertaken to further corroborate the results; the father, however, who should carry the new allele, remained unavailable. The HLA-Cw*0602 allele (1) has been found to be associated with Psoriasis vulgaris in several studies, e.g. by Mallon et al. (2), confirming earlier serologic studies that implicated HLA-Cw6 as a susceptibility marker. The existence of the nucleotide variations described in this report could allow a further characterization of disease susceptibil- ity haplotype and strengthens the need for HLA typing that characterizes the nucleotide sequence comprehensively for anthropological and disease association studies. The sequence of the new allele was submitted to European Molecular Biology Laboratory Nucleotide Sequence Data- base under the accession number AM285029. The name Cw*0617 listed for this sequence has been officially assigned by the World Health Organization Nomenclature Commit- tee in March 2008. This follows the agreed policy that, subject to the conditions stated in the most recent nomenclature report (3), names will be assigned to new sequences as they are identified. Lists of such new names will be published in the following WHO nomenclature report. Correspondence Gottfried F. Fischer Department of Blood Group Serology Medical University of Vienna ª 2008 The Authors Journal compilation ª 2008 Blackwell Munksgaard Á Tissue Antigens 72, 491–505 499