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branchiootorenal syndrome

MIM.113650 8q13.3

Monday 9 May 2005

Branchiootorenal syndrome is an autosomal dominant disorder characterized by sensorineural, conductive, or mixed hearing loss, structural defects of the outer, middle, and inner ear, branchial fistulas or cysts, and renal abnormalities ranging from mild hypoplasia to complete absence. Reduced penetrance and variable expressivity has been observed.

Mutations in EYA1 are known to cause BOR. Mutations in SIX1 and SIX5, which interact with EYA1, were also identified as an additional cause of BOR.


- cochlear malformation
- sensorineural, conductive, or mixed hearing loss
- structural defects of the outer, middle, and inner ear
- Mondini type cochlear malformation
- stapes fixation
- cup-shaped pinnae
- anteverted pinnae
- bilateral prehelical pits

- branchial arch anomalies

  • branchial cysts
  • bilateral branchial cleft fistulas (branchial fistulas)

- stapes fixation
- malformed pinnae
- preauricular pits
- Mondini malformation
- aplasia of the lacrimal ducts.
- high arched palate
- cleft palate
- bifid uvula
- gustatory lacrimation
- branchial cleft fistulas or branchial cysts, usually bilateral

- renal anomalies


- germline mutation in

  • EYA1 gene at 8q13.3 (MIM.601653)
  • SIX1 gene at 14q23 (MIM.601205)
  • SIX5 gene at 19q13.3 (MIM.600963)

See also

- branchial arch syndromes


- Hoskins BE, Cramer CH, Silvius D, Zou D, Raymond RM, Orten DJ, Kimberling WJ, Smith RJ, Weil D, Petit C, Otto EA, Xu PX, Hildebrandt F. Transcription Factor SIX5 Is Mutated in Patients with Branchio-Oto-Renal Syndrome. Am J Hum Genet. 2007 Apr;80(4):800-4. PMID: 17357085

- Melnick M, Bixler D, Nance WE, Silk K, Yune H. Familial branchio-oto-renal dysplasia: a new addition to the branchial arch syndromes. Clin Genet. 1976 Jan;9(1):25-34. PMID: 1248162