The following features point to the risk of developing OHSS: young age, low body weight, polycystic ovarian syndrome (PCOS), profound hyperstimulation protocols with gonadotropin-releasing hormone (GnRH) agonist long protocol cotreatment, high number of preovulatory follicles, high serum E2 levels, high (5000 IU) dose of hCG for final oocyte maturation, hCG use for luteal phase supplementation, and a state of pregnancy. The gene discussed is GNRH1; the disease is ovarian hyperstimulation syndrome.