Strategies for evaluating B*18 allelic diversity by sequence‐based typing applied to studies of a population from Singapore and African‐Americans

Abstract Strategies to resolve B*18 alleles which carry a deletion in intron 1 close to the 5′ end of exon 2 relative to other HLA‐B alleles or a null allele mutation in exon 1 and to resolve ambiguities among allele combinations including B*18 are described. B*18 allele frequencies from volunteer donors recruited for two hematopoietic stem cell registries show the presence of two alleles, B*180101 and B*1802, in a population from Singapore and only B*180101 in African‐Americans.