A new DQB1*03:31 identified by cloning and sequence-based typing
Summary
In the process of HLA typing bone marrow patient and his potential donors, we have identified the novel DRQB1 allele, DQB1*03:31, in the DNA sample of a male, Native American (American Indian) descendant. This allele is present on the haplotype A* 02:01, B* 57:01, C* 06:02, DRB1* 07:01, DRB4* 01:01, DQA1*02:01, DQB1* 03:31. His other haplotype is A*30:02, is A*30:02, B*18:01, C*05:01, DRB1*14:54, DRB3*02:02, DQA1*01:01, DQB1*05:03, which also occurs on the donor. This new allele is identical to DQB1*03:03:02:01-03:03:02:05 in exon 2 except at codon 116 (position 346 b.p. ) where a nucleotide substitution (GTC >ATC) gives rise to a missense mutation – an amino acid change from Valine to Isoleucine.
The name of the new allele – DQB1*03:31 has been officially assigned by the WHO Nomenclature Committee. This follows the agreed policy that subjects to the conditions stated in the most recent Nomenclature report, names will be assigned to the new sequences as they are identified. Lists of such new names were published in the following WHO Nomenclature report. The GenBank accession number is HM998989.1.
Residue 116 is located in the β1-helix of the HLA class II molecule, which is part of the pocket F involved in peptide binding. The new allele contains an amino acid change in the antigen binding site of the HLA protein, which may alter its presenting properties.
Keywords
HLA DQB1, HLA DQ