Functional characterization and exon 2 intron 2 exon 3 gene sequence of HLA-B*2712 as found in a British family

The HLA-B*27 group of alleles has been extensively studied due to the assoc iation of particular B*27 alleles with ankylosing spondylitis (AS). We desc ribe here an HLA-B*27 allele (B*2712) encoding an antigen that lacks reacti vity with B27 monoclonal antibodies (moabs) and alloantisera but reacts wit h some B40/B60 moabs and alloantisera and expresses the Bw6 public epitope. This allele was discovered by the segregation of an HLA-B allele undetecta ble by PCR-SSP within a Caucasian family from the British population referr ed for routine bone marrow transplant HLA typing and found in the haplotype A*29; B*2712; Cw*1203; DRB1*13; DQB1*0603. Serological typing showed a lac k of reactivity with four B27 moabs and four alloantisera but positive reac tivity with moabs and alloantisera specific for B40/B60 and Bw6 public epit opes. Subsequent sequencing showed the closest homology was with B*2708 wit h three mismatches in exon 2 at positions 204, 209 and 210. The intron 2 se quence was identical with other B*27 lineage alleles including a 2 base pai r deletion at positions 95 and 96. The relationship between HLA-B*2712 and reported B60 associations with susceptibility to AS remains to be determine d.