Disorders of Puberty

Question 1

In someone with hypogonadotrophic hypogonadism, the penis is _____________.

Answer 1

completely normal because the maternal hCG stimulates testosterone growth in the baby in the first trimester; however, the second and third trimesters require testosterone from the son, so cryptorchidism would result

Question 2

Puberty requires a normal ____________ axis.

Answer 2

hypothalamic-pituitary

Question 3

Babies usually have a “mini-puberty” at _________ of age.

Answer 3

two months - eighteen

Note: kids have pubertal levels of LH and FSH at this time.

Question 4

LH and FSH will be __________ in girls with Turner syndrome.

Answer 4

extremely high

Question 5

________________ is referred to as gonadarche.

Answer 5

The reactivation of GnRH secretion from the hypothalamus (usually occurring first at night then during the day)

Question 6

_________________ are thought to stimulate GnRH secretion.

Answer 6

KISS-1 neurons

Question 7

What relationship do LH and FSH have before and during puberty?

Answer 7

Prepuberty: FSH is greater than LH
Puberty: LH is greater than FSH

Question 8

Laboratory evaluation of early puberty is unreliable because __________________.

Answer 8

GnRH secretion is pulsatile and usually occurs predominately at night in early puberty

Question 9

Leuprolide is _______________.

Answer 9

an analog of GnRH

Question 10

What is the most sensitive test for evaluating puberty in adolescents?

Answer 10

Give leuprolide and then measure LH and FSH. The gonadotrophic cells are more sensitive during puberty, so there will be a stronger response if a child has entered puberty. Also, LH will be higher.

Question 11

What are the first signs of puberty in boys and in girls?

Answer 11

Boys: enlargement of the testes
Girls: breast buds

Question 12

Why do boys become taller in puberty?

Answer 12

Because puberty is longer in boys

Question 13

What hormone advances bone age?

Answer 13

Estrogen

In fact, this was discovered because a very tall man presented to doctors. He was in his twenties, but because he had a defect in his estrogen receptor, his bone plates had still not fused!

Question 14

The ______________ cause development of pubic hair, axillary hair, and body odor.

Answer 14

adrenarche

Question 15

What is the mean age of initiation of puberty in girls?

Answer 15

It varies by race/ethnicity: 9.5 for AA girls and 10.5 for caucasian girls.

Question 16

Menarche usually occurs at _____________.

Answer 16

twelve years for girls of all races/ethnicities

Question 17

What does Tanner staging comprise in girls and boys?

Answer 17

Girls: pubic hair and breast development
Boys: pubic hair and testicle size

Question 18

What defines “delayed puberty”?

Answer 18

No puberty signs in boys at 14 or girls at 13

or

No menarche fours years after puberty starts in girls or completion of genital growth in males five years after puberty.

Question 19

In terms of bone age, when do boys and girls typically start puberty?

Answer 19

Girls: 10.5 - 11
Boys: 11.5 - 12

Question 20

What is the difference between central and primary/peripheral hypogonadism?

Answer 20

Central: pituitary is not making LH or FSH

Primary/peripheral: tissues are not responding to LH or FSH

Question 21

How can you distinguish between constitutional growth delay and hypogonadotropic hypogonadism?

Answer 21

Four things:

1) . Bone age! Those with CGD will have younger bone ages, while those with HGHG will have bone ages similar to their actual ages.
2) . Adrenarche progresses independently of gonadotrophin (by an unknown mechanism), so boys with adrenarche in the absence of gonadarche is worrisome for HGHG. Absence of gonadarche with absence of adrenarche is less worrisome (i.e., it is more consistent with CGD).
3) . Those with CGD are generally thin, so a heavy child without gonadarche is worrisome.
4) . Disproportionately large arm span is characteristic of late/absence puberty.

Question 22

What is Kallman syndrome?

Answer 22

Absence of GnRH with accompanying anosmia

This occurs because the GnRH neurons and the olfactory neurons originate and travel from the same embryonic tissue.

Question 23

LH and FSH will rise only with ________________.

Answer 23

the disinhibition of GnRH

Question 24

What are some causes of primary ovarian failure?

Answer 24

Turner syndrome (most common) 
Gonadal dysgenesis 
Radiation
Galactosemia
Chemotherapy
Autoimmune (rare) 

Note: all of these will produce hypergonadotropic hypogonadism (aka primary hypogonadism)

Question 25

What are some causes of primary testicular failure?

Answer 25

Klinefelter's
Cryptorchidism
Testicular regression
Radiation (more susceptible to radiation than the ovaries) 
Chemotherapy

Note: all of these will produce hypergonadotropic hypogonadism (aka primary hypogonadism)

Question 26

Endocrinologists make a distinction between complete and incomplete precocious puberty. What is the difference?

Answer 26

Complete is early onset and early progression

Question 27

Precocious puberty is defined as ___________________.

Answer 27

any signs of puberty before age 9 in boys, 8 in caucasian females, and 7 in AA females

“Puberty signs before the lower limit ages.”

Question 28

Precocious puberty is more common in __________, but _____________.

Answer 28

girls; in boys, CNS issues are more common

Question 29

One of the most common CNS causes of hypogonadism is _____________.

Answer 29

hypothalamic hamartoma

Question 30

What is McCune-Albright syndrome?

Answer 30

A somatic mutation in the alpha subunit of GPCR that leads to constant activation; it is fatal if it occurs in all cells

Presenting signs are precocious puberty and café-au-lait spots that follow a dermatome.

Question 31

What are the three main causes of precocious puberty in girls?

Answer 31

Ovarian cyst
Ovarian tumor
McCune-Albright

Question 32

Explain the signs of adrenal-tumor-related precocious puberty.

Answer 32

Lots of virilization (due to the secreted androgens), but small testes due to low LH and FSH

Question 33

Explain familial testotoxicosis.

Answer 33

LH-receptor mutations that lead to it being constitutively active produce excess testosterone which leads to increased testicular size.

Question 34

Dark areolae are indicative of _______________.

Answer 34

elevated estrogen (often from cysts)

Question 35

The most common cause of hypogonadotropic hypogonadism is _____________.

Answer 35

constitutional growth delay

Question 36

How is hypogonadotropic hypogonadism treated?

Answer 36

Boys: testosterone replacement
Girls: initial estrogen replacement alone followed by estrogen and progestin replacement

Question 37

What are the most common causes of gonadotroph-independent precocious puberty in boys?

Answer 37

CAH
Familial testotoxicosis
Leydig cell tumor
hCG-secreting tumor
Exogenous androgens (for example, if grandpa has a testosterone patch and hugs his grandson frequently)

Question 38

How can you distinguish between central and peripheral precocious puberty using GnRH?

Answer 38

Those with peripheral precocious puberty will have prepubertal LH response, while those with central precocious puberty will have a pubertal LH response.

Question 39

Where, in the HPG axis, do estradiol and testosterone accomplish negative feedback?

Answer 39

At the hypothalamus and pituitary

Question 40

What physical changes occur in girls and boys at puberty?

Answer 40

Girls:

• Breast development
• Genital growth
• Maturation of vaginal mucosa
• Uterine growth
• Redistribution of fat
• Menarche

Boys:

• Enlargement of testes (by LH and FSH; the rest are by testosterone)
• Scrotal changes
• Sexual hair
• Deepening of voice
• Penile growth
• Increase in muscle mass

Question 41

Testosterone replacement for boys and estrogen replacement for girls can be offered to treat ____________, though often only reassurance is needed.

Answer 41

constitutional growth delay

Question 42

What disorder presents with hyalinization and fibrosis of the seminiferous tubules?

Answer 42

Klinefelter’s

Question 43

What CNS disorders can cause central precocious puberty?

Answer 43

Anything that damages the sellar area:

• radiation
• infection
• hydrocephalus
• neoplasms

Question 44

Those with precocious puberty are likely to have ___________ bone age.

Answer 44

advanced

Question 45

How do you treat precocious puberty from congenital adrenal hyperplasia?

Answer 45

Give glucocorticoids. Returning the glucocorticoids (and mineralocorticoids, if necessary) back to normal silences the excess ACTH from the pituitary and thus limits the production of androgens.