Townes-Brocks syndrome (Renal-Ear-Anal-Radial (REAR) syndrome) is a rare autosomal dominant disease characterized by renal, anal, ear, and thumb abnormalities.
The major manifestations of this syndrome include:
- renal: displaced or rotated kidneys, horseshoe kidney, polycystic kidney, hypoplastic kidneys
- anal: anteriorly placed, stenotic, or imperforate anus
- ears: abnormally shaped pinna, external auditory canal stenosis, hearing loss
- hands and feet: preaxial polydactyly or syndactyly, triphalangeal thumbs, overlapping foot or toe bones
- cardiac: tetralogy of fallot, defects of ventricular septum
- eyes: congenital cataracts, coloboma, microphthalmia
- periauricular tags and pits
- intellectual disability
It is an autosomal dominant disorder due to a mutation in the SALL1 gene.
CT scan will exhibit external auditory canal stenosis.
Treatment and prognosis
Manage the presenting manifestations of the disease:
- surgical correction of imperforate anus
- treatment of hearing loss early in the disease course
- hemodialysis and renal transplant for ESRD
- surgical correction of congenital cardiac defects
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- 3. Botzenhart EM, Green A, Ilyina H, et al. SALL1 mutation analysis in Townes-Brocks syndrome: twelve novel mutations and expansion of the phenotype. Hum Mutat 2005:26-282.
- 4. Kohlhase J. SALL1 mutations in Townes-Brocks syndrome and related disorders. Hum Mutat 2000: 16:460-6.
- 5. Townes PL and Brocks ER. Hereditary syndrome of imperforate anus with hand, foot and ear anomalies. J Pediatr 1972:81;321-326.