2. Genetic and PCOs

Obvious familial clustering of PCOs and higher prevalence of its sign and symptom, like type 2 diabetes mellitus (T2DM) and hyperandrogenemia in first-degree relatives of women with PCOs, demonstrate its genetic origin [15, 16]. Also, in the Dutch twin study, higher degree of heritability was shown [17]. Initially, autosomal dominant mode of inheritance was suggested [18]; but after a while, researches demonstrate it has more complex inheritance pattern. Despite the progress in genes or loci study, no single gene has been successfully described as the certain responsible gene among all studies [19]. According to microarray analysis results, 14 important genes were recognized: 6 genes were identified as down-regulated genes and 8 genes as up-regulated genes [20]. Another proposed genes are CYP11A, the insulin gene, and a region near the insulin-receptor gene [21]. Also, controlling genes in folliculogenesis and LH receptor and coding genes for TNFalpha, IL-6, and IL-6 receptor can be involved in the pathogenesis of this syndrome [22].
