[Identification of the Novel Allele HLA-B*54:01:11 Detected by NGS Using the Third Generation Sequencing Technology]

To distinguish the ambiguous genotyping results of human leukocyte antigen (HLA), identify a novel HLA-B allele and analyze the nucleotide sequence.

A total of 2 076 umbilical core blood samples from the Zhejiang Cord Blood Bank in 2022 were detected using the next generation sequencing technology (NGS) based on the Ion Torrent S5 platform. Among these a rare HLA-B allele with ambiguous combination result containing a base mutation was identified, and was further confimed by the third-generation sequencing (TGS) based on the nanopore technology.

The NGS typing result of HLA-B locus showed HLA-B* 46:18, 54:06 or HLA-B*46:01, 54:XX (including a base mutation), and nanopore sequencing confirmed the typing as HLA-B*46:01, 54:XX (including a base mutation). Compared with HLA-B*54:01:01:01, the HLA-B*54:XX allele showed one single nucleotide substitution at position 1014 T>C in exon 6, with no amino acid change. The nucleotide sequence of the novel HLA-B*54:XX has been submitted to the GenBank nucleotide sequence database and the accession number OP853532 was assigned.

A ambiguous genotyping of the HLA-B Locus detected by NGS was distinguished by nanopore sequencing and a new HLA-B allele was successfully identified, which was officially named as HLA-B*54:01:11 by the World Health Organization Nomenclature Committee for Factors of the HLA System.