Identification of a novel HLA-DQA1 null allele, DQA10403N, from an East African woman

: 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 α‐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.