There are several examples of common endocrine diseases: type I/II diabetes mellitus, Graves’ disease (GD), polycystic ovary syndrome (PCOS), and insulin-like growth factor I (IGFI) deficiency, etc. To date, genome-wide association studies (GWAS) have reported numerous gene regions associated with different endocrine diseases. This evidence concerns the gene IGF1 and polycystic ovary syndrome.