Ultimately, these conditions of acquired CH impair the function of gonadotroph cells within the anterior pituitary and/or reduce the function of gonadotrophin releasing hormone (GnRH) neurons, and thereby reduce the release of FSH and LH with consequent impaired spermatogenesis and testicular dysfunction in males, and an absence of menstruation and hence sub-fertility in females [14,23]. This evidence concerns the gene GNRH1 and cyclic hematopoiesis.