Waardenburg syndrome type 4A
subtype of Waardenburg syndrome type 4 (Waardenburg-Shah syndrome) caused by mutations in EDNRB
Waardenburg syndrome type 4A is an extremely rare congenital disorder caused by a mutation in an endothelin receptor gene. It results in common Waardenburg syndrome symptoms such as abnormal hair and skin pigmentation and heterochromia, but also present with symptoms of Hirschsprung's disease. Symptoms include abdominal pain and bowel obstruction. Waardenburg syndrome type 4A is the rarest among the types, appearing only once in about every 1,000,000 individuals. There have only been a total of 50 cases reported in total as of 2016.
Presentation
Similar to other types of Waardenburg syndrome, Shah-Waardenburg syndrome patients present with some facial features such the abnormal pigmentation in the hair and premature graying, observed as white forelock. Their eyes also present abnormal pigmentation such as heterochromia iridis or uncharacteristic blue eyes. The study conducted by Shah reported additional physical features such as white eyebrows and eyelashes as well, which is not seen in other types of Waardenburg syndromes.These patients also lack some key features from the Waardenburg syndrome, noted by the lack of dystopia canthorum, the broad nasal root, as well as the lack of white skin pigmentation around the body. Studies have also shown that hearing loss due to EDNRB mutation such as the ones that cause type 4A, have a 53.3% prevalence in patients.
The biggest difference noted is the additional symptoms caused by the additional HSCR which included intestinal obstruction and colonic aganglionosis.
This brief starts where responsible research should: with the source description of “Waardenburg syndrome type 4A” as subtype of Waardenburg syndrome type 4 (Waardenburg-Shah syndrome) caused by mutations in EDNRB. Everything that follows is an evidence route, not borrowed authority.
Why this record matters
The subject matters to the general reference register because the source frames it as subtype of Waardenburg syndrome type 4 (Waardenburg-Shah syndrome) caused by mutations in EDNRB. Its deeper value depends on whether names, dates, institutions and citations support that framing.
Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Apr 4, 2026. The linked authority identifier is Q32145171. None of the 0 selected statements returned an explicit reference. The first chronological checks are 2016.
The absence of detail may reflect summary conventions rather than a lack of surviving documentation. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.
- Subject orientation
- Search vocabulary
- Locating named sources
The closest primary source, responsible institution and strongest cited specialist reference.
Three-step research path
- Establish the record: confirm the title “Waardenburg syndrome type 4A”, its source revision and the description used here.
- Expand the search: follow Waardenburg syndrome type 4A primary sources, Waardenburg syndrome type 4A archive and Waardenburg research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Waardenburg syndrome type 4A”?
- Which institution is responsible for the underlying evidence?
- Which cited source is closest to the event, object or claim?
Search terms from this dossier
This entry incorporates text from “Waardenburg syndrome type 4A” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.