IRF6 and popliteal pterygium syndrome: To date, over 300 different mutations in IRF6, including missense, nonsense, frameshift, microdeletions, splice‐site mutations, and so forth, have been reported to cause VWS, Popliteal pterygium syndrome (PPS, MIM: 119500), Oral clefts and other diseases, of which more than 200 mutations were detected in VWS.