title: HLA-A*02 subtype distribution in Caucasians from northern Italy: identification of A*0220.
abstract: This study describes a comprehensive easy to perform PCR-SSOP typing approach suitable for complete genomic subtyping of HLA-A*02. A single 1.6 kb PCR-amplificate spanning exons 2, 3 and 4 of the HLA-A*02 gene was used for hybridization with a panel of twenty-four SSOPs. This allowed unequivocal assignment of all so far known HLA-A2 subtypes, including A*0209 and A*0215N which differ for nucleotide substitutions in exon 4, without the need for two separate amplifications. Using this approach, HLA-A*02 subtype distribution was analyzed in 218 samples from unrelated, healthy individuals from northern Italy enrolled in the Italian Bone Marrow Registry and typed as HLA-A2 by serology or generic molecular analysis. As expected, A*0201 was found in the majority (92.6%) of samples. However, a significant number (6.8%) of individuals carried A*0205. Furthermore, A*0202, A*0208, A*0209 and A*0217, so far not described in Caucasians, were detected in a low number of samples (frequency ranging from 0.45% to 1.8%). Finally, a novel HLA-A*02 subtype, A*0220, was detected in 0.9% of the samples. As confirmed by DNA sequencing of exons 2 and 3, this allele is identical to A*0201 except for a single nucleotide substitution in codon 66 which changes the predicted amino acid sequence form Lys to Asn. The findings of this study have implications for the selection of HLA-A*02+ donors in unrelated bone marrow transplantation and of patients for specific immuno-therapy with HLA-A*02 restricted peptide vaccines.
authors.affiliation: Department of Biology and Biotechnology (DIBIT), Istituto Scientifico H.S. Raffaele, Milano, Italy.
authors.forename: K
authors.initials: K
authors.lastname: Fleischhauer
authors.forename: E
authors.initials: E
authors.lastname: Zino
authors.forename: B
authors.initials: B
authors.lastname: Mazzi
authors.forename: G M
authors.initials: GM
authors.lastname: Severini
authors.forename: E
authors.initials: E
authors.lastname: Benazzi
authors.forename: C
authors.initials: C
authors.lastname: Bordignon
mesh_terms: D005796:Genes; D015789:HLA-A2 Antigen / Q000145:classification* / Q000235:genetics*; D006801:Humans; D007558:Italy; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D044465:White People
chemical_list: D015789:HLA-A2 Antigen