Characterization and naming of alleles is a prerequisite for the matching of a potential stem cell donor to a patient on a global level. However, HLA genes are the most variable genes in the human body and over 30 000 alleles are known and described in the IPD-IMGT/HLA database (https://www.ebi.ac.uk/ipd/imgt/hla/). Despite the high number of described alleles we are identifying novel variants on a daily basis.

Novel alleles are subjected to two independent full-length PCR reactions and sequenced using two different technologies: Illumina shotgun sequencing and PacBio SMRT sequencing. By combining the data of both technologies, we are able to generate highly correct and fully phased sequencing data (Albrecht et al., 2017; Paech et al., 2021). The final sequences are submitted to IPD-IMGT/HLA using our in-house developed software TypeLoader2 (Schöne et al., 2019). As of today, our team has characterized and submitted more than 6400 novel sequences.