RESUMO
The new allele HLA-B*15:220 is associated with a conserved haplotype.
Assuntos
Alelos , Antígenos HLA-A/genética , Antígenos HLA-B/genética , Antígenos HLA-C/genética , Cadeias HLA-DRB1/genética , Feminino , Haplótipos , Humanos , MasculinoRESUMO
The B*51:79 allele displays a conserved haplotype association with HLA-A*68:01, C*01:02, DRB1*14:01 and DQB1*05:03.
Assuntos
Alelos , Antígenos HLA-B/genética , Haplótipos , Feminino , Antígenos HLA-A/genética , Antígenos HLA-C/genética , Cadeias HLA-DRB1/genética , Humanos , MasculinoRESUMO
Class I allelic typing based on sequencing is reliable, immutable and easy to analyse when only one allele is amplified using a specific mono-allelic technique. A strategy has been developed to selectively amplify exons 2, 3 and 4 of each allele of the three class I loci, previously identified by generic typing, in order to sequence these alleles from their intronic parts in only one direction. This procedure is based mainly on the polymorphism of exon 1 and intron 1 of the HLA-A, -B and -C genes with allele group-specific forward primers and locus-specific reverse primers so as to perform mono-allelic amplification in a 'One Step' pre-sequence-based typing (pre-SBT) PCR. The 5' polymorphism found at each locus is nevertheless not sufficient to discriminate all allelic combinations. Hence exon 2 and exon 3 polymorphism had to be used in a 'Two Step' pre-SBT PCR method to selectively amplify the two alleles in the 1.8%, 7.6% and 0.9% of unresolved combinations found in our laboratory for, respectively, the HLA-A, -B and -C loci. Preparation and validation of 'ready-to-use' aliquots of primer-mixes, pre-SBT buffer and sets of Dye terminator reaction mixtures containing locus-specific intronic primers makes the procedure easy and efficient. The SBT method is the only allelic typing technique used in our laboratory (to date, 742 HLA-A*, 802 HLA-B* and 615 HLA-Cw* alleles have been sequenced) and our successful participation in the national and international quality controls of 4 years ago testifies to the accuracy of the results.