DPB1*8601, a previously unrecognized DPB1 variant in the Caucasoid population.

A new, previously unrecognized DPB1* allele, DPB18601, was found in a Swedish family. The new allele was carried on the common North European haplotype HLA A1-B8-DR3. Both individuals carrying the new allele were initially typed as clear DPB14601,6601 but after family studies and further typing with allele-specific primers it was concluded that a new allele was present together with the common DPB10401. The new allele was investigated by direct sequencing of exon 2 in both forward and reverse directions employing intron primers combined with either an allele-specific sense or anti-sense biotinylated primer for bi-directional sequencing. The new allele is identical to DPB11701 in the five first variable regions. In the sixth region, however, DPB18601 carries the GGPM motif shared by several common alleles such as DPB1*0201 and 0401and 0402.