Identification of a novel HLA-A*02 allele, A*027401*.

:  A novel HLA-A*02 allele was detected in a Caucasian patient from central Italy, requiring a hematopoietic cell transplantation. Direct sequencing identified a variation in one nucleotide position, which was confirmed by cloning. The name A*027401 was officially assigned by the WHO Nomenclature Committee in November 2004 (AY796418, AY796419, AY796420, and HWS10002684). A*027401 differs from A*02010101 by a single G to A substitution at nucleotide position 595 in exon 3. The new variant would lead to a nonsynonymous nucleotide change (GGG to AGG) at codon 175, resulting in a basic Arg in the α-helix of the α2-domain, in place of a non-polar Gly. The presence of an uncommon variation at a highly conserved nucleotide position could have implications in unrelated hematopoietic cell transplantation.