Introduction New Facets in Urea Cycle Disorders INTRODUCTION A. Lowenthal Laboratory of Neurochemistry, Born-Bunge Foundation, Universitaire Instelling Antwerpen, Wilrijk, Belgium This occasion is by no means the first meeting devoted to urea cycle diseases. It has been preceeded by meetings held in the Netherlands and in Spain. Accordingly the justification for a further meeting is not immediately evident. The reason for it is that the problems related to urea cycle diseases are developing fast, as instanced inter alia by I) the relation observed between hyperornithinemia and gyrate atrophy...