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.
OBJECTIVE
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."


CONCLUSIONS
Patients with overlapping features of both syndromes should be screened for SALL1 mutations.
Keegan
C E
CE
Department of Pediatrics, University of Michigan Medical School, Ann Arbor, USA.
Mulliken
J B
JB
Wu
B L
BL
Korf
B R
BR
D000015:Abnormalities, Multiple / Q000235:genetics* / Q000503:physiopathology; D001006:Anus, Imperforate / Q000235:genetics; D001483:Base Sequence; D004252:DNA Mutational Analysis; D004431:Ear, External / Q000002:abnormalities; D005146:Facial Asymmetry / Q000235:genetics* / Q000503:physiopathology; D005260:Female; D006228:Hand Deformities, Congenital / Q000235:genetics; D006319:Hearing Loss, Sensorineural / Q000235:genetics; D006801:Humans; D008297:Male; D008334:Mandible / Q000002:abnormalities; D009154:Mutation / Q000235:genetics*; D013577:Syndrome; D013933:Thumb / Q000002:abnormalities; D014157:Transcription Factors / Q000235:genetics*
C104146:SALL1 protein, human; D014157:Transcription Factors