en Original Article Original Article    Polycystic ovary syndrome (PCOS) is a genetically based disorder which reflects multiple potential aetiologies and variable clinical presentations. It is clearly a heterogeneous syndrome, and current proposed diagnostic criteria include a number of disorders with similar phenotypes but radically different aetiologies. The lack of well-defined diagnostic criteria makes identification of PCOS confusing to many clinicians and seriously delayed the clarification of its genetics, aetiology, clinical associations and assessment of treatment. There is no universally accepted clinical definition for PCOS. In this review the genetic causes and diagnosis criteria of PCOS will be discussed. PCOS, Heterogeneous syndrome, Genetics 1 6 http://ijrm.ir/browse.php?a_code=A-10-549-267&slc_lang=en&sid=1 Mohammad Hasan Sheikhha No Yazd Clinical and Research Center for Infertility, Shahid Sadughi University of Medical Sciences, Yazd, Iran Seyed Mehdi Kalantar smkalantar@yahoo.com Yes Yazd Clinical and Research Center for Infertility, Shahid Sadughi University of Medical Sciences, Yazd, Iran Nasrin Ghasemi No Yazd Clinical and Research Center for Infertility, Shahid Sadughi University of Medical Sciences, Yazd, Iran