Sonographic Diagnosis of Antley-Bixler PORD-Type Syndrome

Antley-Bixler syndrome (ABS)-consisting of ABS type 1 (skeletal only) and ABS type 2, associated with cytochrome 450 mutations and P450 oxidoreductase deficiency (PORD-ABS)-is a heterogeneous syndrome with a constellation of skeletal deformation findings that classically include skull, facial, and appendicular defects. The hallmarks of ABS type 1 include craniosynostosis, midface hypoplasia, radiohumeral/radioulnar synostosis, arachnodactyly, bowing of the femur, congenital fractures, and choanal atresia. ABS has historically been identified at newborn or childhood examination using radiographic, computed tomography, or stillbirth autopsy. However, in recent years, antenatal ultrasonography has identified craniosynostotic conditions in utero. We present a case of PORD with the ABS phenotype diagnosed by sonography in utero at an early gestation (13-16 weeks), which included mutations in the POR gene. Sonographers, sonologists, and perinatologists aware of the diversity of this rare condition will be well prepared to raise the suspicion of Antley-Bixler PORD-type syndrome.