> **Unable to complete cited disease report**
>
> No retrievable papers or citable context IDs were obtained in this run, so a PMID-cited report on EDN3/EDNRB Waardenburg–Shah syndrome cannot be generated.
>
> Attempted retrieval included multiple `paper_search` queries for Waardenburg–Shah syndrome, Waardenburg syndrome type IV, EDNRB, EDN3, Hirschsprung disease, and related endothelin-pathway terms, plus `clinical_trials_search`, `patent_search`, `open_targets_search`, and `gather_evidence`; these returned no usable source contexts or failed.
>
> To proceed, the run needs at least one retrievable authoritative source such as PubMed-indexed papers or PDFs/DOIs, OMIM disease/gene entries, Orphanet disease pages, or a GeneReviews chapter so citable context IDs can be created.


*Blockquote: This blockquote documents why a fully cited disease report could not be produced in the current run. It also summarizes the retrieval steps attempted and the minimum source inputs needed to enable a proper evidence-grounded report.*