A silent mutation in HLA-DPB1*0101 and its evolutionary implications

A novel HLA-DPB1 allele (DPB1*/A6) has been identified in West Africa, and the occurrence of the recently reported allele DPB1*4001 (DPB1*BRI-5) in Negroid populations has been confirmed DPB1*WA6 differs from DPB1*0101 by a silent nucleotide exchange at codon position 43 only. It constitutes, thereby, a link to DPB1*1101, *1501, and *2601 and suggests and evolutionary relationship with these alleles. Carrying the same silent mutation, DPB1*1101, *1501, and *2601 may, by recombinations, have evolved from DPB1*WA6. An apparently older evolutionary branch arose directly from DPB1*0101 and comprises the closely related alleles DPB1*2701 and DPB1*4001 reported only from individuals of African descent.