Induction of puberty in hypogonadal children.

Puberty is the transitional period between childhood and adulthood when physical, sexual, and psychosocial maturation occurs. The onset of puberty is controlled by the gonadotropin-releasing hormone (GnRH) neuron and is triggered when inhibition of the neuron is lifted. Subsequently, GnRH induces secretion of other hormones, follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which in turn stimulate the gonads. Concurrently, increases in estrogen levels in both boys and girls stimulate growth hormone (GH) and insulin-like growth factor-I (IGF-I) secretion, which are responsible for the pubertal growth spurt. In hypogonadal children, however, hypothalamic/pituitary defects or gonadal diseases preclude the production of these hormones, preventing the onset of puberty. Hormone replacement therapy with either estrogen or testosterone is a viable treatment option for hypogonadal children. These should be administered with consideration of sexual maturation rates, statural and bone growth rates, and occurrence of adverse effects. The merits and disadvantages of various hormone replacement therapies for girls and for boys are discussed.