Disorders of Puberty

Question 1

Hallmark of puberty

Answer 1

Increase LH pulses at night

Question 2

Prepuberty

Answer 2

FSH > LH

Question 3

Adrenarche

Answer 3

Result of the development of the zona reticularis (produces DHEA-S and androstenedione)

Generally happens about 2 years before gonadarche)

Question 4

Onset of menses

Answer 4

Generally ~2years after onset of breast development (between Tanner Stage 2-3)

Question 5

First test if concerned about pubertal development

Answer 5

Bone age

Question 6

hCG

Answer 6

Critical for genital development in the first trimester

Question 7

Prader-Willi

Answer 7

Defect on Chr 15 (missing paternal allele); congenital cause of hypogonadotropic hypogonadism

Question 8

First physical signs of puberty

Answer 8

Testicular enlargement > 3mL in boys

Breast bud development in girls

Question 9

Girls- pubertal changes

Answer 9

1. Breast development
2. Genital growth (labia minora)
3. Maturation of vaginal mucosa
4. Uterine/ endometrial growth
5. Female fat distribution changes
6. Androgen changes (pubic hair, axillary hair, body odor, and pimples)
7. Growth velocity increases

Question 10

Boys- pubertal changes

Answer 10

1. Testicular growth (scrotal changes)
2. Penile growth
3. Prostatic growth
4. Seminal vesicle growth/ sperm production
5. Deepening of voice
6. Sexual hair- upper lip, chin, side burns, axilla, pubic area
7. Growth velocity increases

Question 11

Assessment of delayed puberty

Answer 11

If FSH/LH levels are:

High- indicates primary problem (constitutional delay of growth, Klinefelter, Turner, gonadal dysgenesis, Noonan syndrome)

Low- indicates secondary problem (Kallman syndrome, Prader-Willi, excessive exercise, anorexia, chronic illness, malnutrition, hypothyroidism, radiation, trauma, autoimmune)

Question 12

Symptoms of delayed puberty

Answer 12

Girls: No menses by age 16

Boys: No increase in testicular size by age 14

Question 13

Features of precocious puberty

Answer 13

S&S of puberty in

Boys: before 8-9, Girls: before 7-8

Question 14

Causes of precocious puberty

Answer 14

Central: Premature activation of the HPG axis (due to CNS abnormality- 5% in girls and 50% in boys)

Peripheral:

Girls- ovarian cysts, granulosa cell tumor, Sertoli-Leydig tumors, exogenous estrogens

Boys- Adrenal tumor or CAH (pubic hair, growth acceleration, small testes)- increased androgens but low FSH and LH, Leydig cell tumor (unilateral large testicle), hCG secreting tumor (increased T prod, but testes are same size), familial testotoxicosis (LH receptor mutation that self-activates; virilization at 2-3 yrs)

Causes in both genders:
Primary hypothyroidism (TSH cross-reacts with FSH receptor); symptoms- poor linear growth
McCune Albright Syndrome: precocious puberty, >4 cafe au lait spots, polyostotic fibrous dysplasia (bone becomes fibrotic)

Question 15

Evaluation

Answer 15

Hx, growth chart, physical (tanner stage, skin, near), bone age, GnRH sim test or random gonadotropins, karyotype

Question 16

GnRH stim test results

Answer 16

If stim test results in low LH level (<5mIU/dL) : indicates central axis has not been “activated” –> therefore peripheral cause of precocious puberty

If stim test results in high LH level (»5mIU/dL): indicates central axis has been “activated” –> therefore central cause of precocious puberty

Opposite for delayed puberty