The frequency of DRB1*1454 in South German Caucasians.

Human leukocyte antigen (HLA)-DRB1*1454 differs from HLA-DRB1*1401 in only one position in exon 3. Before description of this polymorphism both alleles were routinely typed as HLA-DRB1*1401. This prompted our study on relative frequency of these alleles. We determined relative frequencies of DRB1*1454 and DRB1*1401 by sequence-based tying (SBT) in 106 samples and found DRB1*1454 in 87.9% and DRB1*1401 in 12.1% of previously DRB1*1401/54 ambiguous tested individuals. Population frequencies were estimated using data from the local bone marrow donor database. Phenotype and genotype frequency of DRB1*1454 and DRB1*1401 were 5.592%, 0.2828, and 0.773%, 0.00391, respectively. The corresponding figures for DRB1*1404 were 0.238% and 0.00119. Other DRB1*14 alleles were very rare. The most frequent haplotype was DRB1*1454-DRB3*0202-DQB1*0503. Although DRB1*1454 is almost exclusively associated with DRB3*0202, DRB1*1401 is linked with either DRB3*0201 or DRB3*0202. HLA-DRB1*1454 is the most common DRB1*14 allele among German Caucasians and should be considered as a preferred allele over DRB1*1401.