Identification of an HLA-A11 serological variant and its characterization by sequencing based typing

We have identified an HLA-A11 variant allele, A*1105, segregating in a Cauc asoid family The variant antigen expressed by this allele failed to cross-r eact with most Caucasoid anti-HLA-A11 antisera tested, Sequencing based typ ing has been used to characterize this new allele and this showed that it h as a novel mutation at a polymorphic position (502) in exon 3. In compariso n with A*1101, the mutation (A-->G) results in an amino acid change from po sitively-charged lysine to negative glutamate and this may explain the alte red HLA-A11 serological profile exhibited by this antigen, The new allele w as found in a patient with acute lymphoid leukaemia (ALL), her father and t wo siblings.