In summary, we have demonstrated that macroprolactinemia is a prevalent cause of HPRL among women presenting with menstrual irregularities, galactorrhea, infertility, or alterations in libido attended by gynecology and endocrinology clinic, and we confirmed that the main etiology of MPRL is due to presence of anti-PRL autoantibodies. This evidence concerns the gene PRL and familial hyperprolactinemia.