Six patients with the ectrodactyly-ectodermal dysplasia-clefting (EEC) syndrome, namely five members of the same family and one sporadic case, are presented. One of the main features of the EEC syndrome, ectrodactyly, was missing in five of the patients. The diagnosis did not become clear until the youngest son of the family was born. All of our six patients had a low birth weight and some were born preterm, and four had poly- and/or syndactyly without ectrodactyly. A low birth weight and polysyndactyly have been reported previously in patients with the EEC syndrome and might be features of the syndrome. The present patients illustrate the great phenotypic variability in the EEC syndrome and the need for a careful search for microsymptoms in potential gene-carriers. In two members of the affected family, EEC syndrome was diagnosed prenatally after 16 weeks of gestation by detection of the cleft lip and palate on ultrasound examination. The mother chose to continue the pregnancies. However, prenatal diagnosis of cleft lip and palate might be of value in genetic counselling for other inherited syndromes leading to severe disability.