CLONING AND CHARACTERIZATION OF A NOVEL BICOID-RELATED HOMEOBOX TRANSCRIPTION FACTOR GENE, RIEG, INVOLVED IN RIEGER SYNDROME

Rieger syndrome (RIEG) is an autosomal-dominant human disorder that in cludes anomalies of the anterior chamber of the eye, dental hypoplasia and a protuberant umbilicus. We report the human cDNA and genomic cha racterization of a new homeobox gene, RIEG, causing this disorder. Six mutations in RIEG were found in individuals with the disorder. The cD NA sequence of Rieg, the murine homologue of RIEG, has also been isola ted and shows strong homology with the human sequence. In mouse embryo s Rieg mRNA localized in the periocular mesenchyme, maxillary and mand ibular epithelia, and umbilicus, all consistent with RIEG abnormalitie s. The gene is also expressed in Rathke's pouch, vitelline vessels and the limb mesenchyme. RIEG characterization provides opportunities for understanding ocular, dental and umbilical development and the pleiot ropic interactions of pituitary and limb morphogenesis.