Although the GnRH antagonist protocol has been widely used around the world, it is not so popular in some infertility centers, that is mainly due to cost of the drug as well as the lack of practical experiences among infertility specialist .Therefore, the majority of the studies, focused on administrating antagonist in PCOS patients in order to reduce OHSS occurrence (11). The gene discussed is GNRH1; the disease is ovarian hyperstimulation syndrome.