Characterization of the novel HLA-A*31:11:02 allele by next generation sequencing.

HLA-A*31:11:02 differs from A*31:01:02 by one nucleotide substitution at position 565 in exon 3.

Expression profile of HLA-B*38:55Q allele.

The identification of null or questionably expressed HLA allelic variants is a major issue in HLA diagnostics, because the mistyping of the aberrant expression of such alleles can have a major impact on the outcome of both hematopoietic stem cell transplantation (HSCT) and solid organ transplants. It is debated how questionable (Q) alleles, because of their unknown expression profile, should be considered in an allogenic HSCT setting. The HLA-B*38:55Q allele was detected as an HLA-B blank specificity; DNA sequencing identified a single polymorphism at position 373 in exon 3 (TGC > CGC), which results in the replacement of cysteine 101 with an arginine in the HLA-B heavy chain, thus, impairing disulfide bridge formation in the alpha-2 domain, essential for the normal expression of the HLA molecules.