Precocious and delayed sexual development in children.

A review is presented of tests used to diagnose either isosexual precocity or delayed pubertal development in children. The importance of auxological measurements is emphasised. Attention is drawn to the limitations of measuring basal or stimulated levels of LH, FSH and the sex steroids for the diagnosis of these conditions. The value of gonadotropin profiles is discussed for either diagnosis or for assessing the response to GnRH therapy in patients with either isosexual precocity or isolated gonadotropin deficiency. Examples are given of new therapeutic agents and procedures that are used to treat these two groups of patients. These include GnRH agonists for treatment of children with isosexual precocity either alone, or in combination with inhibitors of aromatase or C17-20 lyase enzyme activity in the biosynthesis of the sex steroids and pulsatile GnRH for the treatment of adolescents with gonadotropin deficiency.