Table 1.

Summary table for unilateral pulmonary artery agenesis

Etiology	Involution of the proximal sixth aortic arch during embryogenesis.
Incidence	1: 300,000.
Gender ratio	None.
Age predilection	Infancy (when other associated defects present). Adulthood (when isolated).
Risk factors	None known.
Treatment	Surgical or medical to prevent/treat pulmonary hypertension. Treatment of respiratory infections, hemoptysis.
Prognosis	Good if asymptomatic. Guarded if progressive pulmonary hypertension.