Long-Read Sequencing in Blood Group Genetics

Background: The key advantages of latest third-generation long-read sequencing (TGS) technologies include the ability to resolve long haplotypes and to characterize genomic regions that are challenging to analyze with short-read sequencing. Recent advancements in TGS technologies have significantly improved accuracy, a crucial requirement for the transition from research to diagnostic applications. Summary: In the field of immunohematology, the adoption of TGS is still in its early stages and published applications are scarce. An undeniable utility of TGS in blood group genomics is the ability to resolve ambiguous genotype-phenotype blood group results. In particular, hybrid genes and other large structural variants, as commonly found in the RHD/CE and MNS blood group systems, cause such discrepant results that can hardly be resolved by conventional methods. Long-read sequencing also greatly aids to generate high-standard reference alleles, establish haplotype sequence databases, or could even serve for high-resolution genotyping of all blood groups in parallel. Additionally, TGS holds the potential to close important knowledge gaps in blood group transcriptomics and epigenetics. Key Messages: The aims of this review were to examine the prospects of TGS technologies within the field of immunohematology and to highlight practical applications. Furthermore, we present a comprehensive overview of the existing and emerging wet-laboratory strategies for data generation, as well as a summary on bioinformatic data analysis methods. Finally, we provide an outlook on anticipated advancements in the near future.