IMGT® analysis of the human IGH locus: unveiling novel polymorphisms and copy number variations in 15 genome assemblies from diverse ancestral backgrounds.

Abstract

Unraveling the genetic complexity of the human immunoglobulin heavy (IGH) chain locus provides valuable insights into the mechanisms underlying the efficacy and specificity of the adaptive immune response. Despite its crucial role, the IGH locus remains insufficiently characterized, with its allelic diversity and polymorphisms inadequately investigated. In this study, we present an analysis of the human IGH locus, incorporating 15 human genome assemblies from diverse ancestries, including African, European, Asian, Saudi, and mixed backgrounds. Through our examination of both maternal and paternal assemblies, we uncover novel IGH alleles, copy number variations (CNV), and polymorphisms, particularly within the variable (IGHV) region. Our findings reveal extensive and previously uncharacterized genetic variability in the constant (IGHC) region and distinct IMGT CNV forms across individuals. This research contributes to a significant enrichment of the IMGT^® IGH reference directory, databases, tools and web resources, and lays the groundwork for an IMGT^® haplotype database which can be progressively enriched as additional datasets become available. Such a resource promises to propel personalized immunogenomics forward, with exciting applications in cancer immunotherapy, COVID-19, and other immune-related diseases.