Ocular malformations and developmental genes.

New insights into the pathogenesis of ocular malformations came with the discovery of transcription factors that determine the fate of cells in the developing eye. Several malformations have been matched to individual developmental genes that share conserved DNA sequences such as the homeobox. These disease/gene matches include the oculorenal syndrome and PAX2; aniridia and PAX6; Rieger syndrome and RIEG1/PITX2; cyclopia and Sonic hedgehog; cone-rod dystrophy, Leber's congenital amaurosis and CRX; and recessive septooptic dysplasia and HESX1. Gene mapping and mutation analysis have allowed a more accurate and meaningful classification of genetically heterogeneous diseases such as the anterior segment dysgenesis syndromes. This paper reviews current information on the genetics of ocular malformations.