Townes-Brocks syndrome versus expanded spectrum hemifacial microsomia: review of eight patients and further evidence of a "hot spot" for mutation in the SALL1 gene

Genet Med. 2001 Jul-Aug;3(4):310-3. doi: 10.1097/00125817-200107000-00007.


Purpose: It can be difficult to differentiate clinically between hemifacial microsomia (HFM) and Townes-Brocks syndrome (TBS). The distinction is important because TBS is inherited as an autosomal dominant trait, whereas HFM is sporadic.

Methods: We performed a retrospective analysis of eight patients with HFM-expanded spectrum and anal anomalies to determine whether this subset has TBS.

Results: Two patients had major phenotypic findings of TBS. Sequencing of SALL1, the gene mutated in TBS, in four of the eight patients revealed one with a C --> T transition (resulting in a nonsense mutation R276X) at a previously identified mutational "hot spot."

Conclusion: Patients with overlapping features of both syndromes should be screened for SALL1 mutations.

Publication types

  • Research Support, U.S. Gov't, P.H.S.
  • Review

MeSH terms

  • Abnormalities, Multiple / genetics*
  • Abnormalities, Multiple / physiopathology
  • Anus, Imperforate / genetics
  • Base Sequence
  • DNA Mutational Analysis
  • Ear, External / abnormalities
  • Facial Asymmetry / genetics*
  • Facial Asymmetry / physiopathology
  • Female
  • Hand Deformities, Congenital / genetics
  • Hearing Loss, Sensorineural / genetics
  • Humans
  • Male
  • Mandible / abnormalities
  • Mutation / genetics*
  • Syndrome
  • Thumb / abnormalities
  • Transcription Factors / genetics*


  • SALL1 protein, human
  • Transcription Factors