Decreased GnRH secretion, and subsequently decreased FSH and LH secretion, may arise due to congenital defects of GnRH production or secretion. It is often difficult to distinguish between patients with hypogonadotrophic hypogonadism, who will never progress through puberty, and those with constitutional delay of growth in adolescence who will develop, albeit at a late age.
Patients with hypogonadotrophic hypogonadism tend to be of normal height until adolescent age when, because of their lack of a growth spurt, they become shorter than age-matched controls.
Patients with idiopathic GnRH deficiency are physically and endocrinologically similar to normal prepubertal children, even at their advanced chronological age.
