PLOD1 and hyperprolactinemia: Hyperprolactinemia suppresses the pituitary-gonadotropin axis by slowing the pulse frequency of GnRH [22–24] with FSH-predominant gonadotropin secretion and simultaneous suppression of LH [25, 26], and this differential regulation (dependent on prolactin levels) may explain the discordance between FSH and LH in this syndrome.