13B - Precocious and Delayed Puberty

Question 1

What triggers the onset of puberty?

Answer 1

Pulsatile secretion of GnRH from the hypothalamic pulse generator.

Question 2

What hormones are released by the anterior pituitary in response to GnRH?

Answer 2

FSH and LH.

Question 3

What is the role of FSH and LH in males?

Answer 3

LH stimulates Leydig cells to produce testosterone; FSH acts on Sertoli cells to support spermatogenesis.

Question 4

What is the role of FSH and LH in females?

Answer 4

LH stimulates theca cells to produce androgens; FSH stimulates granulosa cells to convert androgens to estrogen and progesterone.

Question 5

When does GnRH secretion begin in fetal life?

Answer 5

Around week 4 of intrauterine life.

Question 6

What happens to GnRH, FSH, and LH levels after mid-gestation?

Answer 6

They decline and remain low through childhood.

Question 7

What change in secretion marks the onset of puberty?

Answer 7

Shift to pulsatile GnRH secretion.

Question 8

How does LH vs FSH secretion change during puberty?

Answer 8

LH becomes greater than FSH; earlier pulses occur at night and later also during the day.

Question 9

How does GH secretion change during puberty?

Answer 9

GH secretion increases, driven by sex steroids and increased GnRH activity.

Question 10

What is the role of GH during puberty?

Answer 10

Promotes linear growth and development of secondary sexual characteristics.

Question 11

What causes Kallmann syndrome?

Answer 11

Failed migration of GnRH-secreting neurons and olfactory bulbs.

Question 12

What are the key clinical features of Kallmann syndrome?

Answer 12

Hypogonadotropic hypogonadism and anosmia (loss of smell).

Question 13

What is the hormonal profile in Kallmann syndrome?

Answer 13

Low GnRH, low FSH/LH, low sex steroids.

Question 14

What defines precocious puberty?

Answer 14

Onset of secondary sexual characteristics before age 8 in girls or age 9 in boys.

Question 15

What is central (true) precocious puberty?

Answer 15

Early activation of the HPG axis, GnRH-dependent.

Question 16

What is peripheral (pseudo) precocious puberty?

Answer 16

Independent of GnRH, often due to hormone-producing tumors or adrenal disorders.

Question 17

What are the Tanner stages used to assess?

Answer 17

Development of primary and secondary sexual characteristics during puberty.

Question 18

What is Tanner Stage 1?

Answer 18

Pre-pubertal: no pubic hair, flat chest, small penis/testes.

Question 19

What is Tanner Stage 2?

Answer 19

Breast buds/testicular enlargement; soft pubic hair.

Question 20

What is Tanner Stage 3?

Answer 20

Coarser pubic hair, penile lengthening, breast mound formation.

Question 21

What is Tanner Stage 4?

Answer 21

Pubic hair covers pubis; widening of penis; mound-on-mound breast contour.

Question 22

What is Tanner Stage 5?

Answer 22

Adult genitalia and breast contour; pubic hair extends to thighs.

Question 23

What are primary sex characteristics?

Answer 23

Organs directly involved in reproduction (e.g., testes, ovaries, genitals).

Question 24

What are secondary sex characteristics?

Answer 24

Features like pubic hair, breast development, voice change, not directly involved in reproduction.

Question 25

What is the definition of precocious puberty?

Answer 25

Pubertal development before age 8 in biological females and age 9 in biological males.

Question 26

What is the first sign of puberty in biological females and males?

Answer 26

Breast development in females, testicular enlargement in males.

Question 27

What axis initiates puberty?

Answer 27

The hypothalamic-pituitary-gonadal (HPG) axis.

Question 28

What hormones are released from the anterior pituitary in response to GnRH?

Answer 28

LH (luteinizing hormone) and FSH (follicle-stimulating hormone).

Question 29

What is gonadarche?

Answer 29

Activation of gonads by the HPG axis leading to sex hormone production.

Question 30

What is adrenarche?

Answer 30

Maturation of adrenal glands, producing androgens that cause pubic/axillary hair.

Question 31

What are benign variants of early puberty?

Answer 31

Isolated premature adrenarche, premature thelarche, prepubertal vaginal bleeding, and mini-puberty.

Question 32

What is isolated premature adrenarche?

Answer 32

Appearance of pubic/axillary hair before age 8/9 with normal growth and no other pubertal signs.

Question 33

What is premature thelarche?

Answer 33

Early breast development in girls under 8 with no other signs of puberty.

Question 34

What should be ruled out in a child with prepubertal vaginal bleeding?

Answer 34

Trauma, foreign body, mass, and sexual abuse.

Question 35

What is the first imaging test to assess bone age?

Answer 35

Left-hand X-ray.

Question 36

What indicates pathologic puberty on bone age imaging?

Answer 36

Advanced bone age.

Question 37

What labs are used to assess HPG axis activity?

Answer 37

LH, FSH, estradiol (females), and testosterone (males).

Question 38

What lab pattern suggests central precocious puberty?

Answer 38

Elevated LH/FSH and sex steroids in pubertal range.

Question 39

What are MRI indications in precocious puberty?

Answer 39

Girls <6, all boys <9, or neurological signs (e.g., headaches, vision changes).

Question 40

What is the most common CNS lesion causing CPP?

Answer 40

Hypothalamic hamartoma.

Question 41

What endocrine disorder can mimic CPP?

Answer 41

Severe hypothyroidism.

Question 42

What lab pattern suggests peripheral precocious puberty?

Answer 42

Low LH/FSH with elevated sex steroids.

Question 43

What are common exogenous causes of PPP?

Answer 43

Oral contraceptives, estrogen/testosterone creams, lavender or tea tree oil.

Question 44

What is McCune-Albright syndrome?

Answer 44

PPP with café-au-lait spots, fibrous dysplasia, and endocrine hyperfunction.

Question 45

What is the radiologic hallmark of McCune-Albright syndrome?

Answer 45

Ground-glass bone appearance on X-ray.

Question 46

What signs suggest an ovarian/testicular tumor?

Answer 46

Rapid puberty progression and palpable mass.

Question 47

What tumor markers should be checked for gonadal tumors?

Answer 47

hCG, LDH, AFP.

Question 48

What adrenal findings are associated with virilization in PPP?

Answer 48

Elevated testosterone, 17-OHP, DHEA-S; mass on ultrasound.

Question 49

What distinguishes non-classic CAH from classic CAH?

Answer 49

Non-classic appears in childhood/adolescence without salt wasting; classic presents in infancy.

Question 50

What test confirms non-classic CAH?

Answer 50

ACTH stimulation test showing elevated 17-OHP.

Question 51

At what ages is puberty considered delayed in females and males?

Answer 51

Puberty is delayed if it hasn’t started by age 13 in females and age 14 in males.

Question 52

What system regulates the onset of puberty?

Answer 52

The hypothalamic-pituitary-gonadal (HPG) axis.

Question 53

What hormones are released by the anterior pituitary to stimulate gonads?

Answer 53

Luteinizing hormone (LH) and follicle-stimulating hormone (FSH).

Question 54

What are the primary sex hormones in males and females?

Answer 54

Testosterone in males; estrogen and progesterone in females.

Question 55

What is the Tanner scale used for?

Answer 55

To assess stages of sexual development during puberty.

Question 56

What are primary sex characteristics?

Answer 56

Organs directly involved in reproduction (e.g., testes, ovaries, penis, vagina).

Question 57

What are secondary sex characteristics?

Answer 57

Physical features that emerge at puberty not directly involved in reproduction (e.g., pubic hair, breast development).

Question 58

What defines hypogonadism?

Answer 58

Low levels of sex hormones due to decreased gonadal function.

Question 59

What is primary hypogonadism also known as, and what are LH/FSH levels?

Answer 59

Hypergonadotropic hypogonadism; LH and FSH levels are high.

Question 60

What causes primary hypogonadism?

Answer 60

Gonadal failure, genetic syndromes (e.g., Turner, Klinefelter), trauma, radiation, or chemotherapy.

Question 61

What is secondary hypogonadism also known as, and what are LH/FSH levels?

Answer 61

Hypogonadotropic hypogonadism; LH and FSH levels are low.

Question 62

What causes secondary hypogonadism?

Answer 62

Pituitary or hypothalamic dysfunction, tumors, chronic illness, malnutrition, stress, or excessive exercise.

Question 63

What is constitutional delay of puberty?

Answer 63

A non-pathologic, familial delay in puberty onset that eventually resolves.

Question 64

How is delayed puberty diagnosed?

Answer 64

Tanner scale assessment, hormone level testing, and medical/family history.

Question 65

What is the treatment for constitutional delay?

Answer 65

Typically none; puberty starts naturally. Monitoring is advised.

Question 66

What is the treatment for hypogonadism-related delayed puberty?

Answer 66

Hormone replacement therapy and, if needed, fertility treatments.

Question 67

What happens if delayed puberty is not treated in pathologic cases?

Answer 67

Risk of permanent infertility and incomplete sexual development.