Popliteal Pterygium Syndrome, also known as autosomal dominant popliteal pterygium syndrome, is related to van der woude syndrome 1 and syngnathia. An important gene associated with Popliteal Pterygium Syndrome is IRF6 (Interferon Regulatory Factor 6), and among its related pathways/superpathways are NF-kappaB Signaling and Wnt / Hedgehog / Notch. Affiliated tissues include skin and uterus, and related phenotypes are joint stiffness and cleft palate