Originally described as distinct syndromes, the G
and BBB syndromes are now summarized as a single disorder characterized by
hypertelorism, hypospadias. and other midline defects. In particular,
congenital heart defects are frequent and include patent ductus arteriosus,
atrial septal defect, ventricular septal defect, coarctation of the aorta,
and complex malformations, such as tetralogy of Fallot and double-outlet
right ventricle (conotruncal anomalies). A variety of genitourinary defects
other than hypospadias, such as cryptorchidism, bifid scrotum, and
imperforate anus, also belong to the phenotypic spectrum of Opitz syndrome.
Other facial anomalies include cleft lip and palate, a broad, flat nasal
bridge, micrognathia, and up-slanting or down-slanting palpebral fissures
with epicanthal folds. Frequent anomalies are laryngeal malformation (or
cleft) and a high carina or tracheoesophageal fistula. Dysphagia associated
with recurrent aspiration is common. Achalasia of the esophagus and/or
hiatus hernia. MRI may show absent or hypoplastic corpus callosum, or
cortical atrophy with ventriculomegaly. Mild-to-moderate mental deficiency
with hypotonia.