title: Identification of a novel HLA-DQA1 null allele, DQA1*0403N, from an East African woman.
abstract: We report a novel DQA1 allele (DQA1*0403N) identified during sequence-based HLA-DQA1 typing of a Kenyan population. The new allele is identical to DQA1*0401 at exon 2 except for a single-nucleotide substitution at codon 53, changing it from lysine to a stop codon (CAA-->TAA). The substitution at codon 53 was confirmed by sequencing two separate polymerase chain reaction products and by sequencing multiple clones obtained following TOPO-TA cloning. The resulting stop codon at position of codon 53 in exon 2 is predicted to produce a non-functional DQA1 alpha-chain. The new allele has been named by the WHO nomenclature committee as DQA1*0403N. This is the first report of a null allele detected in the DQA1 gene.
authors.affiliation: Department of Medical Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Luo
authors.forename: C R
authors.initials: CR
authors.lastname: Cohen
authors.forename: M J
authors.initials: MJ
authors.lastname: Narayansingh
authors.forename: S
authors.initials: S
authors.lastname: Pan
authors.forename: L
authors.initials: L
authors.lastname: McKinnon
authors.forename: R C
authors.initials: RC
authors.lastname: Brunham
authors.forename: F A
authors.initials: FA
authors.lastname: Plummer
mesh_terms: D000328:Adult; D001483:Base Sequence; D018389:Codon, Nonsense; D005260:Female; D006683:HLA-DQ Antigens / Q000235:genetics*; D059848:HLA-DQ alpha-Chains; D006801:Humans; D007630:Kenya; D008969:Molecular Sequence Data; D016415:Sequence Alignment
chemical_list: D018389:Codon, Nonsense; D006683:HLA-DQ Antigens; D059848:HLA-DQ alpha-Chains; C069050:HLA-DQA1 antigen