The Working Group recognized that when a laboratory evaluates genes for the specified categories of variants recommended here as incidental findings, the analysis may not be technically equivalent to examining these genes as a primary finding. For example, sequencing could have areas of diminished or absent coverage in the genes examined for incidental findings that would be filled in by Sanger sequencing or other supplementary approaches if the gene were being evaluated for a primary indication. In addition, while genome sequencing can provide increasingly reliable information on copy number variation and translocations, exome sequencing is currently less reliable, and neither technology can be used to measure tandem repeat size accurately. For these reasons, we did not include some disorders where structural variants (e.g., translocations and inversions), repeat expansions, or copy number variations are the primary cause, and have not recommended that laboratories utilize orthogonal techniques to search for these variants in the genes named in the minimum list. Thus, the Working Group recommended that laboratories evaluate these genes for the specified categories of variants to the extent that the available
