Unilateral pulmonary atresia with total sacral agenesis and other congenital defects.

Is there a common aetiologic element in the VACTERL syndrome and the caudal regression syndrome? We report a boy who fulfilled three criteria of the VACTERL association (he had thoracic hemivertebra, high anal atresia and tracheo-oesophageal fistula) but also could be classified as caudal regression syndrome on the basis of the anal atresia and total sacral agenesis. We discuss the arguments in favour of both diagnosis.