Introduction: Townes-Brocks syndrome is constituted by a multi-systemic pattern of congenital anomalies with autosomal dominant inheritance. The most characteristic defects are those affecting hearing and the auricle, anal atresia and thumb anomalies.
Patients and methods: We present the epidemiological characteristics of six cases of Townes-Brocks syndrome identified in the consecutive series of 25,967 malformed live born infants detected among 1,431,368 live births surveyed by the ECEMC (Spanish Collaborative Study of Congenital Malformations) between April 1976 and June 1997.
Results and conclusions: The minimal estimated frequency of Townes-Brocks syndrome in our data is 0.42 cases per 100,000 liveborn infants. These infants have low birth weights. Similar to other published studies, we have observed in our cases a wide variation in the clinical expression of the syndrome, showing great inter-family, as well as intrafamily variability.