branchiootorenal syndrome
MIM.113650 8q13.3
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.
Synopsis
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
- mild hypoplasia
- bilateral renal agenesis (renal aplasia)
- bilateral non-obstructive renal dysplasia (BNORD)
- renal collecting system anomalies (anomalies of the collecting system)
- polycystic kidneys
Etiology
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
References
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