In comparison to long GnRH agonist protocols, the risk of severe OHSS is reduced by approximately 50% in a GnRH antagonist protocol for ovarian stimulation prior to in vitro fertilisation (IVF) or intra-cytoplasmic sperm injection, while the two protocols provide equal chances of pregnancy per initiated cycle [6]. The gene discussed is GNRH1; the disease is ovarian hyperstimulation syndrome.