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.
Keegan, Catherine E. MD, PhD 1; Mulliken, John B. MD 2; Wu, Bai-Lin PhD 3; Korf, Bruce R. MD, PhD 3
[Article]
Genetics in Medicine.
3(4):310-313, July/August 2001.
(Format: HTML, PDF)
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.
(C) 2001 Lippincott Williams & Wilkins, Inc.