Three new DPB1 alleles identified in a Bantu-speaking population from central Cameroon

HLA-DPB1 genotyping of 241 individuals from an African Bantu-speaking population in central Cameroon using sequence-specific oligonucleotide probes identified five individuals with novel probe hybridization patterns. DNA sequence analysis of the second exon of the DPB1 alleles from these five individuals identified three new alleles, *6001, *6101N, and *6201. DPB1*6001, found in two individuals, contains a single nucleotide change that results in a polar amino acid, asparagine, at residue 65; this position in the pr domain is occupied by a nonpolar amino acid in all other reported DPB1 alleles. DPB1*6101N, found in one individual, contains a single base mutation that results in a premature termination codon at position 67. DPB1*6201, found in two individuals, is characterized by the apparent motif shuffling that has been hypothesized to be responsible for the majority of DPB1 sequence polymorphism. These new sequences shed additional light on the potential mechanisms by which allelic diversity is generated at the HLA-DPB1 locus.