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
Ce. Keegan et al., 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, 3(4), 2001, pp. 310-313
Purpose: It can be difficult to differentiate clinically between hemifacial
microsomia (HFM) and Townes-Brocks syndrome (TBS). The distinction is impo
rtant because TBS is inherited as an autosomal dominant trait, whereas HFM
is sporadic. Methods: We performed a retrospective analysis of eight patien
ts 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 patient
s revealed one with a C --> T transition (resulting in a nonsense mutation
R276X) at a previously identified mutational "hot spot." Conclusion: Patien
ts with overlapping features of both syndromes should be screened for SALL1
mutations.