Two children are described with the combination of aplasia cutis congenita (ACC) and transverse limb defects known as Adams-Oliver syndrome. Whereas in the first child the typical features of ACC, syndactyly and transverse nail dystrophy were only mildly expressed and associated defects of the central nervous system and cardiac malformations were absent, the second child suffered from a very severe expression of the syndrome, with a combination of ACC, syndactyly, cutis marmorata telangiectatica congenita and multiple cardiac and central nervous system malformations which resulted in fatal central respiratory insufficiency.