Frequencies and haplotype associations of non-expressed HLA alleles in ethnically diverse populations on the National Marrow Donor Program’s Be The Match Registry

Sequencing of two novel HLA class I null alleles, A*32:160N and B*14:113N, produced by single‐nucleotide mutations

“…Despite the high number of HLA class I null alleles, only a few of them have been described as Common alleles according to their population frequency. 2 In this report, we describe two novel HLA class I null alleles in the HLA-A and -B loci found in two Spanish bone marrow donors. HLA typing by next-generation sequencing (NGS) rendered A*32:01:01:01 and B*14:01:01:01 variant alleles with nucleotide point mutations at exons 3 and 5, respectively.…”

“…Most of these non‐expressed genes are generated by point mutations, insertions and deletions provoking a premature stop codon and a truncated nonfunctional protein. Despite the high number of HLA class I null alleles, only a few of them have been described as Common alleles according to their population frequency 2 …”

HLA Class I Molecules as Immune Checkpoints for NK Cell Alloreactivity and Anti-Viral Immunity in Kidney Transplantation

“…Among both HLA-B and -C (as well as -A) there are now many alleles identified that are not expressed, the so called null alleles. Although their frequencies in the population are very low ( 104 ), the impact on NK alloreactivity is huge. Therefore, high resolution typing of HLA-A, -B and -C, according to the standards of the European Federation for Immunogenetics (EFI) taking null alleles into account, would be the definite correct way of determining NK ligand presence.…”

Genomic sequence of the novel HLA‐A*26:206:02N allele, identified in a patient with hepatitis B infection

“…The HLA‐A gene encodes highly diverse transmembrane proteins that present viral peptides to T‐cells and launch pathogen‐specific immune responses 1 . The frequency of null HLA alleles in the general population is low and estimated about 2.30e‐04 2,3 . The number of null HLA alleles recognized has increased over the past few years, with a total of 410 null HLA‐A alleles being reported in the IPD‐IMGT/HLA Database (http://www.ebi.ac.uk/ipd/imgt/hla) by August 2023 4 .…”