The disease-associated genes include IRF6, NECTIN1, CDH1, MSX1, etc. For instance, Van der Woude syndrome (VWS, OMIM#119300), a dominant-inherited developmental disorder characterized by frequent occurrences of upper lip and/or palate clefts, constitutes the most prevalent orofacial cleft syndrome and accounts for 2% of all CL/P cases [13]. The gene discussed is IRF6; the disease is van der Woude syndrome.