1. Differential diagnosis Anorectal malformations may occur in association with numerous other malformations'0 and as part of a very large number of syndromes." Among these, the disorder likely to feature most prominently in the differential diagnosis of the Townes-Brocks syndrome is the VATER association, in which there is a high incidence of anal atresia (56%), renal dysplasia or agenesis (44%), and congenital heart defects (73%). 12 Anomalies of the ears (39%) and thumbs (28%) occur less commonly. In an isolated case, distinction between the almost invariably sporadic VATER association and the Townes-Brocks syndrome may be very difficult. The presence of vertebral defects or tracheo-oesophageal malformations or both would strongly favour the former diagnosis