Identification, sequencing and serology of HLA-B*3527.

We describe a variant HLA-B35 allele (B3527) that was detected by the polymerase chain reaction using sequence-specific primers (PCR-SSP) in an individual on the Welsh Bone Marrow Donor registry. B3527 differs from B3501 by a single base (G/A) at position 302 that encodes an amino acid change of Ser to Asn at position 77 in the Bw6 epitope. Serological studies using 38 B35-, 4 Bw6- and 7 Bw4-reactive sera indicated that the B3527 product was indistinguishable from the B35 specificity, and that the substitution did not significantly affect the Bw6 epitope. A family study determined the B3527 bearing haplotype as: HLA-A29, B3527, Cw0401, DRB10404, DRB40101/0103, DQA103, DQB1*0302, BFS, C4A3, C4B1. The phenotype and gene frequencies in the local Welsh population were<0.01% and <0.00005%, respectively.