> **Response to user request (blocked)**
>
> No citable source contexts were retrieved in this session, so a comprehensive, well-cited report on EDN3/EDNRB Waardenburg–Shah syndrome cannot be generated here.
>
> Retrieval attempts for literature, clinical trials, patents, and disease-target evidence did not yield usable source contexts, and OpenTargets queries failed after retries.
>
> The most useful substitute artifacts prepared in this run are the retrieval audit, the blocker/constraint summaries, and the next-action input package describing what sources are needed to enable a fully cited follow-up report.
>
> To proceed, the next run should be seeded with retrievable PMIDs, DOI links, PDFs, or authoritative OMIM, Orphanet, and GeneReviews sources so citable context IDs can be created.


*Blockquote: This blockquote explains why the requested evidence-backed report could not be produced in the current session. It also points to the key substitute artifacts and the source inputs needed for a successful follow-up run.*