Truncus arteriosus (TA) is a rare congenital cardiovascular anomaly characterized by a single arterial trunk arising from the heart by means of a single semilunar valve (<I>i.e.</I> truncal valve). Pulmonary arteries originate from the common arterial trunk distal to the coronary arteries and proximal to the first brachiocephalic branch of the aortic arch. TA typically overrides a large outlet ventricular septal defect (VSD). The intracardiac anatomy usually displays situs solitus and atrioventricular (AV) concordance.

A genital phenotype that is not clearly assignable to a single gender. Ambiguous genitalia can be evaluated using the Prader scale: Prader 0: Normal female external genitalia. Prader 1: Female external genitalia with clitoromegaly. Prader 2: Clitoromegaly with partial labial fusion forming a funnel-shaped urogenital sinus. Prader 3: Increased phallic enlargement. Complete labioscrotal fusion forming a urogenital sinus with a single opening. Prader 4: Complete scrotal fusion with urogenital opening at the base or on the shaft of the phallus. Prader 5: Normal male external genitalia. The diagnosis of ambiguous genitalia is made for Prader 1-4.