A report of a twin pair, monochorionic diamniotic, born at 29 weeks of gestation in which both twins developed severe ROP with retinal detachment suggests that the synergistic effects of unstable cardiopulmonary status and genetic predisposition due to VEGF 936C>T polymorphism caused the development of severe ROP [104]. This evidence concerns the gene VEGFA and retinopathy of prematurity.