PITX2 and persistent hyperplastic primary vitreous: In Kelberman's study, 1 patient had retinal detachment due to PHPV.[11,12] For PITX2-positive ARS, a few reports indicated the presence of retinal detachment associated with proliferative vitreoretinopathy or PHPV.[13–15] Akihisa Matsubara presented a hypothesis on the mechanism and critical period for the occurrence of PA, PHPV, and maldevelopment of the iris, which states that migratory disorders of neural crest cells from 4 to 7 weeks of gestation are responsible for the malformation complex.