Interlink of Two Syndromes - Demarquay-van der Woude and PoplitealPterygium in One Family Group

Background and Objective: Demarquay-van der Woude (DVWS) and Popliteal Pterygium (PPS) syndromes are distinct autosomal dominant conditions generally presenting with a cleft lip and/or cleft palate. Both syndromes are genetically associated with mutations of the gene coding for Interferon Regulatory Factor 6 (IRF6) and grouped together as the IRF6-Related Disorder. In addition to a cleft, DVWS characteristically includes generally two labial pits on the lower lip. The pits may be symmetrical or asymmetrical, with saliva draining from them, or may also be abnormally flabby or conical-shaped mucosal elevations without distinct pitting. In PPS, the cleft patient commonly presents with an extensive single lower lip pit with salivary drainage, as well as popliteal webs/pterygia of the lower limb/limbs. Additional defects may include intraoral synechial web, syndactyly and genito-urinary malformations. Methods: One case (infant) with two family members presented with overlapping deformities associated with DVWS, as well as PPS. Sequencing of the IRF6- gene was performed on one of the members. Results: The surgical records of 4182 patients of a major cleft lip and palate clinic recorded 71 (1.70%) patients diagnosed with DVWS, 12 (0.29%) with PPS and one infant (0.02%) as an interlinked DVWS-PPS. In the family of the baby presented in this paper, all three affected individuals are females and each the third child in the family, who have lip pits typically associated with DVWS that are both bilateral and symmetrical. The grandmother and grandchild, but not the mother, has underdeveloped or minor unilateral popliteal webs. All three have syndactyly of their feet with hypoplastic toenails (involving one to three phalanges) and pyramidal-shaped (or redundant) skin above the hallux nail of the main phalanges. Conclusion: The infant and two family members are identified as interlinked DVWS-PPS.