Morphology of the sella turcica in Axenfeld–Rieger syndrome with PITX2 mutation

Background:  Axenfeld–Rieger syndrome (ARS) is a rare autosomal dominant disorder with an incidence of 1:200 000. Genotype and phenotype are heterogeneous and clinical morphology impresses with variable expressivity. Additionally to the typical craniofacial and dental aberrations anomalies in the morphology of sella turcica are discussed. Method:  In a multidisciplinary genetic and clinical study four patients of a family with ARS were screened by direct DNA sequencing. Radiographic analysis of the patients was performed for evaluating cranial and dental structures. Additionally, a specific analysis of the morphology of the sella turcica was made on the radiographs. Results:  Screening for PITX2 and FOXC1 mutations revealed a P64L missense mutation in PITX2 in all four patients. The cephalometric analysis showed a midface hypoplasia associated with a skeletal Class III. All patients showed a sella turcica bridge combined with a prominent posterior clinoid process followed by a steep clivus and an elongated sella turcica. Conclusion:  The incidence of a sella turcica bridge in combination with a PITX2 mutation would suspect that sella turcica anomalies are typical symptoms of the syndrome. Sella turcica anomalies in association with craniofacial and dental aberrations, such as maxillary retrognathia, skeletal Class III relationship and hypoplasia of teeth, might be important indicators for ARS caused by PITX2 mutation.