Two new HLA class I alleles recognised by PCR sequence-specific primer and sequencing based typing: B*3805 and Cw*0408.

Two new HLA class I alleles have been recognised by molecular-based typing. B * 3805 was initially identified by polymerase chain reaction using sequence-specific primers (PCR-SSP) and afterwards confirmed by sequencing based typing (SBT) studies in a Spanish Caucasian blood cord unit. A unique nucleotide change throughout exons 2, 3 and 4, leading to the amino acid replacement Ser11Ala, differentiates B * 3801 and * 3805. This position behaves as a dimorphic residue in HLA-B and -C loci, and seems to be structurally unrelated to peptide and TcR recognition. Cw * 0408 was first detected by SBT in two African American bone marrow donors in combination with its most structurally related allele, Cw * 04011. The single amino acid change found between Cw * 04011 and Cw*0408 was Thrl63Leu, a residue involved in pocket A of the peptide-binding cleft. This new allele could be the result of a gene conversion event between Cw * 04011 and any of the Cw * 03 alleles.