Analysis and verification of a HLA-DQB1*03:90N allele with a single base deletion

Abstract

To verify a HLA-DQB1*03:90N allele and method to improve the accuracy of HLA typing. A total of 2265 hematopoietic stem cell donors from Shenzhen Branch of China Marrow Donor Program in 2018 were initially detected by a PCR sequence-specific oligonucleotide probe (SSOP) method. Among these, a rare HLA-DQB1 allele was identified by sequence-based tying (SBT) and Ion Torrent S5 next generation sequencing (NGS). The SSOP typing result suggested the HLA-DQB1 to be a rare allele, while an insertion and a deletion was suspected in its exon 2 by SBT, which were confirmed by NGS as DQB1*03:90N and DQB1*06:01, respectively. Rare alleles suspected by the SSOP method should be verified by other methods to ensure the accuracy of HLA genotyping. Rare alleles formed by deletions can be detected by NGS with accuracy.