Somatic mutation of HLA‐DRB1*04:03 in a patient with myelodysplastic syndrome at diagnosis

Identification of a single nucleotide deletion in the novel HLA-DQB1*06:379N allele, detected by Polymerase Chain Reaction-Sequence Based Typing but not by Next Generation Sequencing

In this report we describe the characterization of a novel null HLA-DQB1 allele, detected by polymerase chain reaction-sequence-based typing but not by next-generation sequencing (NGS). The new allele, HLA-DQB1*06:379N, was discovered in an Italian patient with acute myeloid leukemia and also in one of her healthy siblings. The new allele is largely homologous to DQB1*06:02:01:01 with a T deletion in exon 2, in codon 11, which causes a frameshift and the formation of an unusual and premature TGA STOP in codon 27. This case report underlines the importance of not removing Sanger method sequencing from routine use for high-resolution HLA typing, but to maintain it together with NGS technology.

Somatic mutation in the two HLA-B genes of a patient with acute myelogenous leukemia

In this report, we describe a case of somatic mutations in the two HLA-B genes in a patient with acute myelogenous leukemia. The HLA-B*15:01 allele showed an insertion of two nucleotides within exon 2 leading to a premature stop codon. HLA-B*40:01 showed one nucleotide substitution within exon 3, identical to that described for B*15:258N. The restriction of these mutations in leukemic cells was confirmed in patient's samples from buccal epithelial cells and hematopoietic cells obtained when the patient was in remission. The clinical significance of somatic HLA mutations in cancer seems to be associated with escape from immune surveillance and clonal evolution. The analysis of possible mutations in HLA genes of tumor cells would be valuable information for the outcome of the disease and stem cell donor selection.