Branchio-oto-renal (BOR) dysplasia, syndrome, or spectrum disorder is a rare syndromic disorder characterized by cervical branchial apparatus anomalies, ear malformations, and renal anomalies. If there are no renal anomalies, then it is more likely to be branchiootic dysplasia.
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Pathology
When family history is absent, the diagnosis is established by 3 major criteria, or 2 major and 2 minor criteria 6. An affected individual with an affected first-degree relative only needs to meet one major criterion 6.
Major criteria, with examples 6-8:
- second branchial apparatus (arch/cleft) anomalies
- preauricular pits
- auricular malformation
- deafness (conductive, sensorineural, or mixed hearing impairment)
- renal anomalies
Minor criteria, with examples 6-8:
- preauricular tags
- external auditory canal anomalies
-
middle ear anomalies
- ossicular chain malformations
-
inner ear anomalies
- cochlear anomalies, most commonly hypoplasia of the apical turn
- cochlear aperture stenosis
- dysplasia of lateral and/or posterior semicircular canals
- enlarged vestibular aqueduct
- abnormal course of the facial nerve
- other: facial asymmetry, palate abnormalities
Genetics
It carries an autosomal dominant inheritance. Most families with the branchio-oto-renal syndrome have mutations of the EYA1 gene, found on chromosome 8q.
Radiographic features
CT
Specific features on temporal bone CT include the following:
- "unwound cochlea," where the middle and apical turns are anteromedially rotated and displaced away from the basal turn 8
- medialized course of facial nerve (medial to cochlea) 9
Various additional findings on temporal bone CT are common 8,9:
- cochlear apical turn hypoplasia
- deficiency of the modiolus
- funnel-shaped internal auditory canal
- patulous Eustachian tube
Treatment and prognosis
Some individuals progress to end stage renal failure (ESRF) later in life.