(743) Identification of a novel HLA Allele by Next-Generation Sequencing in Côte d’Ivoire, West Africa

Introduction/Rationale: HLA frequencies are well documented in developing countries, but Africa has lagged behind in genetic research and HLA testing although having the highest HLA diversity in the world. This study aims to improve knowledge on the HLA polymorphism in Africa for both population genetic research and clinical transplantation.

Methods: HLA typing was performed by next-generation sequencing (NGS) using Nanotype kits for 11 loci (Omixon, Werfen) on 200 unrelated donors collected at the Abidjan Blood Centre. All individuals were documented by a very complete demographic questionnaire including data on residence, ethnicity and language over 3 generations. Novel sequence was confirmed using HLA genotyping NGMix reagents (Etablissement Français du Sang, France) run on the Illumina MiSeq sequencing system (Illumina, California). The reads were analysed with the Typestream Visual software (One Lambda, version EFS 2.0).

Results: A novel HLA-C*07 allele named as HLA-C*07:1194N was identified in an Ivoirian (Côte d’Ivoire, West Africa) blood donor. The novel HLA-C*07:1194N allele has a one nucleotide substitution when compared to the HLA-C*07:01:01:01 allele at position 410 where C→T (codon 70 CAG→TAG) in exon 2, resulting in an amino acid change from glutamine to stop codon. The nucleotide sequence of the novel HLA-C allele has been submitted to GenBank with accession number PV568332 and to the IPD-IMGT/HLA Database with accession number HWS10100975. The name HLA-C*07:1194N has been officially assigned by the WHO Nomenclature Committee for Factors of the HLA System in June 2025

Conclusion: This study expands the current understanding of HLA diversity in Côte d’Ivoire by identifying a novel null allele, HLA-C*07:1194N. These findings underscore the need for broader HLA mapping across the continent. Such data are essential to improve donor matching and strengthen transplantation programs in Africa.