Genetics of ventral forebrain development and holoprosencephaly.

The disease holoprosencephaly is the basis of the most common structural anomaly of the developing forebrain in humans. Numerous teratogens when administered during early gastrulation, have been associated with this condition. Recent studies have characterized molecules expressed in the prechordal plate which are critical for normal brain formation. Perturbation of signaling pathways involving these molecules have been shown to cause holoprosencephaly in humans and other organisms.