HLA class I genotyping by cDNA sequence of a Vietnamese family expressing a weak B46 antigen

Serological heterogeneity in HLA-B46 antigens has been described. Previous studies have identified B*4601 as the allele encoding the "strong" B46 antigen found in Chinese populations. Serological characterization of a Vietnamese family revealed a "weak" B46 antigen. Complementary DNA for the HLA-A, B and C alleles of three family members were cloned and the coding regions sequenced. The allele encoding the weak B46 antigen has the same coding sequence as B*4601, demonstrating that the antigenic differences are not due to polymorphism in the amino acid sequence of the HLA-B heavy chain. The recently described HLA-B*1525 and HLA-Cw*0403 alleles were also found to segregate in this Vietnamese family.