Early Antenatal Sonographic Findings of Rubinstein-Taybi Syndrome: Imaging of High-Arched Palate and Bilateral Abducted Thumbs on Surface Rendering Mode at 17 Weeks.

Introduction Rubinstein-Taybi Syndrome (RSTS) is a rare genetic disorder (estimated birth prevalence 1 in 100,000 to 125,000). Rubinstein and Taybi originally described seven children with typical dysmorphic facial features, broad thumbs and toes, and varying degrees of mental retardation. The syndrome is associated with multiple systemic anomalies. The literature includes about a thousand reported cases since 1963. This condition is inherited in an autosomal dominant pattern, but the majority of cases are derived by de novo mutation. It may be caused by micro deletion within 16p13.3 or different mutations in the genes encoding the transcriptional coactivator CREB-binding protein and E1A-binding protein p300. The cytogenetic anomalies of RSTS remain unknown in about 37 % of patients. The diagnosis is based on clinical presentation during the early postnatal period (Spena S et al. J Pediatr Genet 2015; 4: 177-186). Only three cases of antenatal ultrasound diagnosis or detection have been reported to date. Here we present the ultrasound features of a new case.