Identification of the novel allele HLA-DRB1*1137 which probably originatedfrom DRB1*11011: implications for mismatch with its ancestor allele at bone marrow transplantation

The identification of the new allele HLA-DRB1*1137, which was found in a Ca ucasian individual, is described. In the sequence analysis the new allele d iffers from DRB1*11011 by position 227 (T>A) which is located in exon 2. At the protein level, the new allele has one amino acid difference compared t o DRB1*1101 (Phe47Tyr). Residue 47 is likely to contribute to the peptide b inding site of HLA-DR11 and thus to be important for peptide binding. Howev er, as phenylalanine and tyrosine have very similar physical and chemical f eatures allogenicity in case of mismatch at bone marrow transplantation may be weak.