Cornelia de Lange syndrome (CAS) is characterized by facial dysmorphism; hirsutism; internal organ anomalies, including diaphragmatic hernia, and limb defects. While causative mutations in three genes have been identified the etiology of a significant number of cases remains unknown. We report on a child with an 8p23.1 deletion with features of CdLS and congenital diaphragmatic hernia. We review cases with cytogenetic anomalies involving 8p23.1, discuss a potential relationship between 8p23.1 deletions and CAS and suggest a novel candidate gene for CdLS-Tankyrase 1. (C) 2008 Wiley-Liss, Inc.