A familial case of popliteal pterygium syndrome

Popliteal pterygium syndrome (PPS) is a rare malformation disorder characterized by autosomal dominant inheritance, highly variable expressivity and incomplete penetrance. The disorder is caused by the mutation of the IRF6 gene and the respective protein, which belongs to a family of nine transcription factors and is involved in the differentiation and proliferation of keratinocytes. Mutations in the IRF6 gene give rise to popliteal pterygium syndrome, Van Der Woude syndrome and nonsyndromic orofacial clefts. The anomalies from which affected patients suffer can be subdivided into alterations of the orofacial region, the musculoskeletal system and the genitals. Diagnosis is difficult, as is differential diagnosis, due to the variability of the manifestations. Prenatal diagnosis is possible by means of sequence analysis of the IRF6 gene in DNA extracted from the chorionic villus or amniotic fluid, or by means of intrauterine ultrasound. The prognosis is generally good, with normal mental development and the possibility to correct most of the alterations through targeted surgery. The case presented in this study involves two patients: a father and daughter who suffer from PPS, of whom the former was not diagnosed at birth. The two patients have undergone numerous operations over the years on various parts of the body and sequence analysis of the IRF6 gene, which revealed the presence of a mutation in the target site.