Novel HLA allele, HLA-B*4013, identified from a potential bone marrow recipient. Putative gene conversion events with donor sequence

A new B40 allele was identified in a leukemic Caucasian patient. This allel e, designated B*4013, differs in alpha 1 domain from B*4002 at six amino ac idic positions: 67, 77, 80, 81, 82 and 83. Most of this substitutions could alter the antigen binding site of the HLA-B molecule. B*4013 may have orig inated by gene conversion or reciprocal recombination involving B*4002 as t he recipient allele of sequence donated by B*4406. The new allele was serol ogically typed as a "blank" associated with the Bw4 epitope.