Disorders of Puberty Flashcards
1
Q
Physiologic and physical changes associated with puberty
A
- “Reemergence” of GnRH –> stimulates gonadotropes to secrete FSH and LH
- Act at ovaries and testes to promote gonadal maturation & production of sex steroids (estradiol and testosterone)
- Gonadarche
- Adrenarche - other component of puberty
- Starts a couple years before gonadarche
- Refers to increased production of androgens (DHEA-S and androstenedione) from adrenal gland
- First physical sign of puberty is:
- Boys: testicular enlargement > 3mL
- Girls: breast bud development
2
Q
Signs of puberty in girls
A
- Breast development
- Genital growth (labia minora)
- Maturation of vaginal mucosa
- Uterine/endometrial growth
- Female fat distribution changes
- Androgen changes
- Pubic hair, axillary hair, body odor, pimples
- Increased growth velocity
3
Q
Signs of puberty in boys
A
- Penile growth
- Scrotal changes
- Prostatic growth
- Seminal vesicle growth & sperm production
- Deepening of voice
- Sexual hair
- Upper lip, chin, sideburns, axilla, pubic area
- Increased growth velocity
4
Q
Evaluation of puberty/disorders of puberty
A
- Delayed puberty evaluated based on gonadotropin status
- Increased gonadotropins (hypergonadotropic hypogonadism) –> primary gonadal failure
- **Decreased **gonadotropins (hypogonadotropic hypogonadism) –> hypothalamic or pituitary immaturity or dysfunction
- Late bloomers
- Most common cause of delayed puberty w/ low gonadotropins = constitutional delay of growth/puberty
5
Q
Normal age of pubertal onset
A
- Normal
- Boys: 9-14 years old - mean 11.8 years
- Girls:
- Breast development: 10.5 years
- Menarche: 8-13 years
- Caucasian mean age 12.5
- African-American mean age 12.06
- Hispanic mean age 12.25
- Delayed puberty: defined as lack of onset, or lack of normal progression of puberty
6
Q
Definition & causes of delayed puberty
A
- Defined
- Boys with delayed puberty have no testicular enlargement by age 14
- Girls with delayed puberty have:
- No breast development by age 13 years
- No menses 4 years after pubertal onset
- No menses by age 16 years
- Onset of puberty usually commensurate with child’s biological age (bone age)
- Causes:
- Results from lack of maturity of HPA axis or from gonadal dysfunction
- Puberty is delayed but follows a normal progression
- Timing is commensurate with bone age
7
Q
Hypogonadotropic hypogonadism: reversible or functional causes
A
- Decreased LH and decreased FSH
- Reversible or functional causes
- Chronic illness
- Malnutrition
- Stress
- Excessive exercise –> middle and high school athletes, major weight loss
- Anorexia nervosa
- Hyperprolactinemia
- Hypothyroidism
8
Q
Hypogonadotropic hypogonadism: permanent forms
A
- Congenital disorders
- Kallmann syndrome - GnRH deficiency associated with anosmia/hyposmia (lack or reduced sense of smell); kidney malform
- Congenital hypopituitarism
- Midline CNS defects
- DAX-1 gene mutation
- Prader-Willi Syndrome - 70% have GnRH deficiency
- Boys with cryptorchidism
- Girls with primary amenorrhea
- Acquired
- CNS lesions such as pituitary or hypothalamic tumor
- Trauma
- Radiation
- Infection
- Infiltrative disease
- Autoimmune hypophysitis
9
Q
Hypergonadotropic hypogonadism: congenital causes
A
- Increased LH and increased FSH “easiest diagnosis ever”
- Primary gonadal failure has no negative feedback on gonadotropins
- Congenital causes:
- Klinefelter’s syndrome (47,XXY)
- Turner Syndrome (45,XO or 46,X/abnormal)
- 100% short stature relative to family
- 94% ovarian failure - variable other presentations include dysmorphic facies, increased otitis frequency, thyroiditis, CV
- 46,XX or 46,XY gonadal dysgenesis
- Vanishing testes syndrome
- Noonan syndrome - AD, causes abnormal development in many parts of body
10
Q
Hypergonadotropic hypogonadism: acquired causes & further evaluation
A
- Acquired causes:
- Chemotherapy, irradiation to pelvic region, galactosemia, autoimmune torsion or trauma, mumps orchitis, cryptorchidism
- Further evaluation:
- Bone age, gonadotropin levels, testosterone, estradiol, thyroid labs, prolactin, CBC, ESR, BMP, karyotype, sense of smell, height and growth rate
11
Q
Precocious puberty: definition
A
- Dx made when pubertal development begins before defined lower limits
- Boys: before age 9
- Girls:
- Caucasian: before age 8
- African-American/Hispanic: before age 7
12
Q
Complete vs. incomplete precocious puberty
A
- Complete precocious puberty = early onset AND progression of pubertal development
- Evidence of linear growth acceleration
- Evidence of bone age advancement
- May have early closure of growth plates
- Incomplete precocious puberty
- Premature thelarche (onset of breast development)
- Premature adrenarche (onset of increased androgens)
13
Q
Causes of precocious puberty: central/gonadotropin dependent
A
- Due to premature activation of HP-gonadal axis
- Pubertal events normal, just early
- 5% of girls have CNS abnormality
- 50% of boys have CNS abnormality –> image all with diagnosis
14
Q
Causes of precocious puberty: peripheral/gonadotropin independent in girls
A
- May result from CNS abnormalities disrupting stimulatory and inhibitory balance
- Independent of GnRH and gonadtropin stimulation
- In girls, excess estrogens may be caused by:
- Ovarian cysts
- Granulosa cell tumor (super rare)
- Sertoli-Leydig tumors (super rare)
- Exogenous estrogens (birth control pills, premarin)
- May show effects of androgens including pubic and axillary hair, acne, oily skin
15
Q
Causes of precocious puberty: peripheral/gonadotropin independent, in boys
A
- In boys, key to diagnosis is testes
- Adrenal tumor + congenital adrenal hyperplasia
- Pubic hair, growth acceleration, small testes
- Increased androgens but no FSH and LH
- Leydig cell tumor - lots of testosterone, large testicle
- hCG secreting tumor - increased T production but no large testes
- Familial testotoxicosis
- Present at 2-3 years with slight big testes and super high T + huge penises
- LH receptor mutation that activates self
