J Genet Med.  2015 Jun;12(1):44-48. 10.5734/JGM.2015.12.1.44.

Variable expression observed in a Korean family with Townes-Brocks syndrome caused by a SALL1 mutation

• Seo YJ
• Lee KE
• Ko JM
• Kim GH
• Yoo HW

• KMID: 2055589
• DOI: http://doi.org/10.5734/JGM.2015.12.1.44

Abstract

Townes-Brocks syndrome (TBS) is a rare genetic disorder characterized by the classic triad of congenital anomalies of the anus, thumbs, and ears, with variable expressivity. Additionally, renal malformations, cardiac anomalies, and endocrine and eye abnormalities can accompany TBS, although less frequently. TBS is inherited in an autosomal dominant fashion; however, about 50% of patients have a family history of TBS and the remaining 50% have de novo mutations. SALL1, located on chromosome 16q12.1, is the only causative gene of TBS. SALL1 acts as a transcription factor and may play an important role in inducing the anomalies during embryogenesis. Clinical features of TBS overlap with those of other multiple anomaly syndromes, such as VACTERL syndrome, Baller-Gerold syndrome, Goldenhar syndrome, cat eye syndrome, and Holt-Oram syndrome. Consequently, there are some difficulties in differential diagnosis based on clinical manifestations. Herein, we report a Korean family with two generations of TBS that was diagnosed based on physical examination findings and medical history. Although the same mutation in SALL1 was identified in both the mother and the son, they displayed different clinical manifestations, suggesting a phenotypic diversity of TBS.

Keyword

Townes-Brocks syndrome; SALL1 protein; human; Imperforate anus; Polydactyly; Sensorineural hearing loss

MeSH Terms

Anal Canal
Animals
Anus, Imperforate
Cats
Diagnosis, Differential
Ear
Embryonic Development
Eye Abnormalities
Family Characteristics
Female
Goldenhar Syndrome
Hearing Loss, Sensorineural
Humans
Mothers
Physical Examination
Polydactyly
Pregnancy
Thumb
Transcription Factors
Transcription Factors