Some studies have shown polymorphisms of the PCOS related gene for fibrillin 3 (FBN3), gonadotropin-releasing hormone receptor (GnRHR) and CYP1B1 encoded to function for estradiol hydroxylation, all of which may be involved in the pathogenesis of HT and PCOS [29]. The gene discussed is GNRHR; the disease is hematocrit.