Puberty - Paamoni

Question 1

What depresses the HPO axis before puberty?

What removes the depression?

Answer 1

1. Hypersensitivity to estrogen negative feedback
2. Central nonsteroidal suppression of GnRH and gonadotropins synthesis

Gonadarche:
Alteration and amplification of GnRH-gonadotropins, Gonadotropins-ovarian interactions:

• Depression of the CNS-pituitary gonadostate
• Progressive responsiveness of the anterior pituitary to GnRH
• Follicle reactivity to FSH and LH, LH pulsatiles at first during sleep then during the day

Question 2

What are manifestations of puberty in the female and male?

Answer 2

Females:

1. Thelarche (breast growth)
2. Pubarche
3. Axillary hair growth
4. Physical development
5. Psychological changes
6. Menarche (caused by gonadal estrogen secretion)
7. 5 years from telarche to menarche on average (+/- 1 year)

Males:

Question 3

What is adrenarche and what controls it?

Answer 3

Increased production of adrenal androgens causes the growth of pubic and axillary hair

The adrenarche does not appear to be under direct control of gonadotropins or ACTH

Question 4

When are the classifications of precocious puberty?

Answer 4

Before the age of 8

1. GnRH-Dependent Precocious Puberty
   True precocious puberty.
   Complete, isosexual, central (or specifically GnRH- and gonadotropin-dependent) precocity
   Increase associated with IGF-I, can be caused by tumors
   Early activation of the HPO axis.
   Diagnosis by excluision
   Causes short stature
2. GnRH-Independent Precocious Puberty.
   Incomplete, isosexual or heterosexual, peripheral or precocious pseudopuberty.
   may be due to extra pituitary secretion of (HCG) or sex steroid secretion independent of HPO stimulation.
   Ovarian tumor is most common cause

Question 5

What is McCune- Albright syndrome?

Answer 5

Polyostotic fibrous dysplasia

• Accounts for 5% of female precocity
• Autonomous early production of estrogen by the ovaries
• FSH and LH levels are low, respond poorly to GnRH stimulation
• Absence of nocturnal gonadotropin pulsations (all unlike central precocity)
• Multiple disseminated cystic bone lesions that easily fracture
• Cafe au lait skin spots of various sizes and shapes
• Sexual precocity.
• Ovarian cysts
• GH and prolactin-secreting adenomas
• Hyperthyroidism
• Adrenal hypercortisolism,
• Osteomalacia.
• Premature menarche may be the first sign of the syndrome..

Question 6

What laboratory tests are done for precocious puberty?

Answer 6

Bone age.
Head CT scan or MRI, ultrasonography of abdomen and pelvis.
FSH, LH, HCG assay.
Thyroid function tests (TSH and free T 4).
Steroids (serum DHAS, testosterone, estradiol, progesterone, 17-hydroxyprogesterone).
GnRH testing
(if at pubertyal levels- central, also test tolerance, LH will be low with GnRH administration in McCune Albright).

Question 7

What is delayed puberty?

What are some etiologic possibilities?

What laboratory tests can be done?

Answer 7

Patients who have not developed signs of puberty by age 17 (usually from a specific problem)

Delayed puberty is a rare condition in girls, and a genetic problem or hypothalamic-pituitary disorder must be suspected.

• Hypergonadotropic hypogonadism (Turner syndrome or normal karyotype ovarian failure), hypothyroidism, etc.
• Eugonadism

x-rays for bone age
skull imaging (if hypogonadotropic)
gonadotropin and prolactin levels
adrenal and gonadal steroid measurements
thyroid function.
screening for systemic disorders.
Patients with elevated gonadotropins require a karyotype.
IGF-I, IGFBP-3, and IGFBP-2 can distinguish between delayed puberty and growth hormone deficiency;