Annotation of IGH assemblies. Diagrams depicting genes detected in donors’ IGH assemblies. Empty cell indicates deletion of a gene, and a split cell indicates duplication of a gene. The color of the cell corresponds to the matched allele sequence from the IMGT database; sequences with no identical match are denoted as “novel.” Genes are split by groups: V genes (A), D and J genes (B), and C genes (C). In A, a novel structural variant is denoted by an asterisk and represents a large tandem duplication of IGHV3-23 and/or IGHV3-23D, giving a total of seven copies of IGHV3-23. In C, IGHG4 and its duplicate (sometimes termed IGHG4A or IGHG4D) are joined on one row. The red dotted line indicates a duplication extending from IGHE to IGHA1.