The popliteal pterygium syndrome is a congenital malformation that includes orofacial, cutaneous, musculoskeletal, and genital anomalies. The minimal diagnostic criteria for popliteal pterygium syndrome are any three of the following namely cleft lip/palate, popliteal pterygium, paramedian lower lip sinuses, genital and toe nail anomalies .
Cleft palate with or without cleft lip has been found to be the most frequent anomaly in popliteal pterygium syndrome, being present in 91 to 97% of cases. Cleft lip occurs in 58% and lower lip pits or sinuses occur in 45.6% of cases. Popliteal webbing in 58%, syndactyly in 50%, genitourinary anomalies in 37% and nail anomalies in 33% of cases. Other reported clinical features include syngnathia, ankyloblepharon, talipes, and digital reduction defects. There is no growth disturbance and intelligence is usually normal. All cases in our reported family had cleft lip, cleft palate, lower lip sinus and bilateral popliteal pterygium which fulfill the PPS diagnostic criteria.
The genetic locus for PPS has been localized to chromosome 1. The disorder is inherited in an autosomal dominant manner and is due to a mutation of the IRF6 gene. Mutation of RIPK4 gene on chromosome 21 has been identified to be the cause of autosomal recessive PPS. Most reported cases are sporadic; advanced parental age is found in a number of these cases, suggesting new mutations . In our reported family, the father has PPS and mother is normal. The parents and siblings of the father are normal which suggests a new mutation in the father for PPS and then transmitted to his daughters in an autosomal dominant manner. Differential diagnosis includes two groups; the syndromes with similar orofacial anomalies  and disorders with similar limb defects . The first group includes cleft lip and palate syndromes, van der Woude's syndrome, which presents with paramedian lower lip pits and cleft lip/palate and is inherited as an autosomal dominant trait [7,8]. The second group includes lethal PPS and PPS with ectodermal dysplasia. Both are autosomal recessive disorders. Although both conditions feature a cleft lip/palate, syngnathia, and popliteal pterygium, they are clinically distinguishable from the autosomal dominant case. Lethal PPS is differentiated by the presence of microcephaly, corneal aplasia, ectropion, bony fusions, hypoplastic nose and absent thumbs, while PPS with ectodermal dysplasia is differentiated by the presence of woolly hair, brittle nails, ectodermal anomalies, and a fissure of the sacral vertebrae .
Patients have to undergo a series of operations for correction of the congenital anomalies. In the newborn period the ankyloblepharon and oral synechia are corrected to enable eye opening and proper feeding. Cleft lip and palate repair are done in consecutive sessions starting around 2-3 months of age. Early surgical intervention for the popliteal webs appears to be important with respect to long term results. During the operation special attention needs to be given to the vessels and nerves within the pterygium. Postoperatively, plaster casts and physiotherapy are used to ensure good long term results.
The role of MRI in evaluating the normal or abnormal position of the popliteal artery and peroneal nerve provides useful information for preoperative planning for surgical correction of the popliteal pterygium. Operations include excision of the fibrous band, mobilization of nerves and vessels and Z-plasty of the skin . Recurrence of flexion contracture is noted in some cases. Gradual soft tissue lengthening with an Ilizarov external fixator can be one of the optimal procedures when excision of a fibrous band and Z-plasty are not possible due to severe adhesion of the nerves and vessels into a fibrotic band .