Identification of two novel HLA class II alleles, DQB1*030503 and DRB1*0447

Two novel human leukocyte antigen (HLA) class II alleles have been identified in routine typing of bone marrow donors for the Australian Bone Marrow Donor Registry in Sydney, Australia. Sequence analysis of exon 2 of both the DQB1 and DRB1 genes revealed the novel polymorphism. A silent substitution of G to A at nucleotide position 210 has been identified for the DQB1*030503 allele when compared to the closest matched allele, DQB1*030501. There is no associated amino acid difference between the translated products of the two alleles. The second new allele is a variant of the DRB1 gene. The DRB1*0447 allele was identified with three nucleotide substitutions compared to the closest matched allele DRB1*0436. There is a silent mutation at nucleotide position 303, G to C and two substitutions at adjacent nucleotide positions 344 and 345, T to G and G to T, respectively. The latter two substitutions result in an amino acid change from valine to glycine at position 86, implicating a different specificity and affinity of antigen binding.