Identification of a novel HLA-DQA1 null allele, DQA1*0403N, 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 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.

[1]  S. Marsh.  Nomenclature for factors of the HLA system, update June 2003. , 2003, Tissue antigens.

[2]  R. Brunham,et al.  High-resolution sequence typing of HLA-DQA1 and -DQB1 exon 2 DNA with taxonomy-based sequence analysis (TBSA) allele assignment. , 1999, Tissue antigens.

[3]  N. Mehra,et al.  MHC class II alleles and haplotypes in patients with pemphigus vulgaris from India. , 1996, Tissue antigens.

[4]  U. Gyllensten,et al.  HLA DQ-DR haplotype and susceptibility to cervical carcinoma: indications of increased risk for development of cervical carcinoma in individuals infected with HPV 18. , 1996, Tissue Antigens.

[5]  M. King,et al.  MHC class II alleles associated with clinical and immunological manifestations of HIV-1 infection among children in Catalonia, Spain. , 1996, Tissue antigens.

[6]  V. Wahn,et al.  Mite allergy, clinical atopy, and restriction by HLA class II immune response genes , 1996, Pediatric allergy and immunology : official publication of the European Society of Pediatric Allergy and Immunology.

[7]  A. Cambon-Thomsen,et al.  HLA class II associations with idiopathic nephrotic syndrome in children. , 1994, Tissue antigens.

[8]  A. Arnaiz-Villena,et al.  Both class I and class II HLA antigens are thyroid cancer susceptibility factors. , 1994, Tissue antigens.

[9]  L. Hammarström,et al.  Different amino acids at position 57 of the HLA-DQβ chain associated with susceptibility and resistance to IgA deficiency , 1990, Nature.

[10]  G. Francis,et al.  HLA‐DRβ, ‐DQα, and ‐DQβ restriction fragment length polymorphisms in multiple sclerosis , 1989, Journal of neuroscience research.

[11]  E. Thorsby,et al.  Evidence for a primary association of celiac disease to a particular HLA-DQ alpha/beta heterodimer , 1989, The Journal of experimental medicine.

[12]  J. Todd,et al.  HLA-DQβ gene contributes to susceptibility and resistance to insulin-dependent diabetes mellitus , 1987, Nature.