Fig. 1: Flow chart of DNA breakpoint assay (DBA) from sample entry to variant classification.

The number of samples, families, and unique alterations entering the DBA (level 1) filtered by successful DBA and tandem finding (level 2); multiple, unrelated carriers versus a single carrier (level 3); breakpoint clustering versus disparate breakpoints (level 4); variants eligible for reclassification (level 5); and finally, variants that were assigned a pathogenic classification with number of individuals receiving a positive test result represented in parentheses (level 6). UTR untranslated region