The common phenotypic features of Branchio-Oto-Renal Syndrome are hearing loss (incidence 93%), preauricular pits or tags (82%), renal anomalies (67%), branchial fistulae (49%), pinnae deformity (36%) and external auditory canal stenosis (29%). The severity of hearing loss ranges from mild to profound and can be conductive, sensorineural and mixed. In addition to external auditory canal stenosis atresia occurs. Middle ear anomalies can include malformation, malposition, dislocation or fixation of the ossicles, and reduction in size or malformation of the middle ear cavity. Inner ear malformations include cochlear hypoplasia, enlargement of the cochlear and vestibular aqueducts, and hypoplasia of the lateral semicircular canal.(Chen, Francis et al. 1995). Renal anomalies range from hypoplasia to aplasia, either unilaterally or bilaterally. Anomalies of the collecting system affect the ureter, calyx and renal pelvis. (Fraser, Ayme et al. 1983; Heimler and Lieber 1986; Konig, Fuchs et al. 1994).

(Based on a page at the University of Iowa.)