Which statement best explains the mechanism behind central precocious puberty?

Which statement best explains the mechanism behind central precocious puberty?

• A. Peripheral hormone excess
• B. Early activation of the HPG axis
• C. Delays in bone age maturation
• D. LH/FSH suppression

Answer: (B)

Central precocious puberty happens when the brain’s puberty trigger—the hypothalamic-pituitary-gonadal axis—activates earlier than usual. This means GnRH starts being released in a pulsatile way from the hypothalamus sooner, which tells the pituitary to secrete LH and FSH. Those gonadotropins then stimulate the gonads to produce sex steroids (estrogen or testosterone), leading to early development of secondary sexual characteristics, growth acceleration, and an advanced bone age. This mechanism is different from a peripheral form, where sex hormones come from the gonads or adrenals independent of GnRH and do not involve early activation of the HPG axis. An LH/FSH-suppressing state would not produce puberty, and delayed bone age maturation wouldn’t explain early pubertal signs since the bone age is typically advanced in central precocious puberty.

Central precocious puberty happens when the brain’s puberty trigger—the hypothalamic-pituitary-gonadal axis—activates earlier than usual. This means GnRH starts being released in a pulsatile way from the hypothalamus sooner, which tells the pituitary to secrete LH and FSH. Those gonadotropins then stimulate the gonads to produce sex steroids (estrogen or testosterone), leading to early development of secondary sexual characteristics, growth acceleration, and an advanced bone age. This mechanism is different from a peripheral form, where sex hormones come from the gonads or adrenals independent of GnRH and do not involve early activation of the HPG axis. An LH/FSH-suppressing state would not produce puberty, and delayed bone age maturation wouldn’t explain early pubertal signs since the bone age is typically advanced in central precocious puberty.