Facial development involves a complex and highly integrated series of events that are frequently disturbed resulting in a wide variety of craniofacial anomalies. Dissection of the molecular events underlying such conditions has provided insights into the fundamental mechanisms driving normal facial development and how these are disrupted in congenital anomalies. There are numerous craniofacial syndromes each of which provides a unique opportunity to study a particular aspect of morphogenesis. The inheritance patterns that underlie these conditions are variable and include Mendelian and non- Mendelian modes of transmission. The integration of molecular biology, cell biology, experimental embryology, human and mouse genetics has allowed the molecular pathology underlying an increasing number of these conditions to be elucidated. By consideration of Treacher Collins syndrome and some forms of cleft lip and cleft palate this review has it focus on the progress that has been made in recent years within this field. Nevertheless, despite this progress in understanding the molecular pathology of these (and other) disorders of facial development and the consequent increase in our knowledge of the fundamental mechanisms driving facial development, significant challenges remain.
Keywords: Treacher Collins syndrome, cleft lip, cleft palate