“…Future directions to narrow the diagnostic gap may include whole genome sequencing (with the caveat of variant-interpretation challenges), targeted sequencing panels with single-molecule molecular inversion probes, and possibly brain tissue transcriptome analysis with total RNA sequencing. [98][99][100] Narrowing the diagnostic gap may help provide closure to families and caregivers and may also help in the development of target-specific therapies. Current diseasespecific therapies remain limited, and patient outcomes are often guarded.…”