Townes-Brocks syndrome

Townes-Brocks syndrome (Renal-Ear-Anal-Radial (REAR) syndrome) is a rare autosomal dominant disease characterized by renal, anal, ear, and thumb abnormalities.

Clinical presentation

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

Pathology

It is an autosomal dominant disorder due to a mutation in the SALL1 gene.

Radiographic features

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

Differential Diagnosis