HLA-B*44:138Q: Evidence for a confined deletion and recombination events in an otherwise unaffected HLA-haplotype.

We discovered a new HLA-B allele, HLA-B*44:138Q, and confirmed its segregation. For characterisation, we used serology, sequence specific oligonucleotide (SSO), sequence specific primer (SSP), and full length sequencing by Sanger and next-generation sequencing. From an evolutionary point the 5' part of the new allele is identical with alleles from the HLA-B*44:02 group, while its 3' part is identical to the HLA-B*15:18:01:02 allele, the breakpoint being located somewhere between intron 3 and exon 4. The salient feature of the new allele is a deletion of codon 94 in exon 3, which is unique for HLA-alleles reported so far. Gene conversion can be hypothesised in the generation of this HLA sequence; however, the deletion seems to have occurred additionally. Other HLA-alleles of the new allele's haplotype were common alleles.