Identification of HLA-A*2306

We describe a novel allele encoding HLA-A23: A*2306, discovered in an Afric an-American individual, whose DNA was HLA typed as part of a quality contro l exercise. Direct sequencing typing identified A*2301 and A*6601 with an u nexpected heterozygous peak at position 331. As position 331 is at the end of exon 2, near the priming site for the B3.6 antisense sequencing primer, the sequencing data is not optimal in this region and sequencing from the s ense primer is relied on. In addition the new polymorphism was not at an ex pected polymorphic position and could easily have been missed, leading to t he assignment of A*2301. However, data from reference strand mediated confo rmation analysis showed distinct new mobilities from those expected for A*2 301 with two different fluorescent-labelled references, leading to the conc lusion that the heterozygous peak seen at position 331 was a true variant o f the A*2301 allele, A*2306 is most similar to A*2301 with 1 nucleotide dif ference at position 331 in exon 2 which was previously a conserved position . This mutation results in an amino acid substitution of glutamine for glut amate at residue 87.