Puberty and its disorders

Question 1

What is Puberty?

What are the 2 endocrinological events that take place?

Answer 1

• Development of Secondary sexual characteristics - Growth spurt, Production of mature gametes by gonads
• Adrenarche (Pubarche) and Gonadarche

Question 2

ADRENARCHE (PUBARCHE):
What occurs here?

Where in the Adrenal gland is the secretion from?

What is secreted? What do they cause?

What happens with this secretion at its target tissue?

What is Pubarche?
→ What is it associated with?

What is Precocious puberty?

Answer 2

• Gradual increase in Adrenal Androgen secretion
• ZONA RETICULARIS
• Dehydroepiandrosterone (DHEA) & DHEAS - for PUBARCHE
• Converted to Testosterone/DHT
• Appearance of pubic and axillary hair due to adrenarche
  → ACNE - ↑Sebum production, Infection, Abnormal keratinisation
• Puberty before 8 yrs (Female) or 9 yrs (Male)

Question 3

GONADARCHE:
When does it occur?

What’s it driven by?

What is secreted? What do they activate?

In which week is the HPG-axis activated and when does GnRH secretion begin?

What occurs with the GnRH production until Gonadarche?

Answer 3

• After Adrenarche
• HPG-axis
• LH and FSH, which activate gonadal function
• Activation of HPG axis in WEEK 16, and pulsatile GnRH secretion occurs until baby is 1-2yrs old
• GnRH neurons restrained post-natal for >10yrs, and reactivated at Gonadarche
  o Reactivation leads to production of Gonadal steroid production and Secondary gametes/sexual characteristics

Question 4

PHYSICAL CHANGES:
Men:
What are some of the physical changes that occur?

Women:
What are some of the physical changes that occur?

What is Menarche?

Answer 4

- • Deepening of voice
• Facial, Body, Pubic and Axillary hair
• Growth of Internal and External Genitalia
• Fertility
• Height

• • Thelarche (Breast enlargement)
  • Growth of Internal and External Genitalia
  • Menarche
  • Fertility
• Onset of Menstruation

Question 5

Growth Spurt:
Which 2 hormones are involved here?

How does Oestrogen affect bone growth?

Psychological Changes:
What are the 3 changes?

Consonance:
What is it?

What are the 5 Tanner stages measured based?

Answer 5

• GH and Oestrogen
• • Low levels = Linear growth and Bone maturation
  • High levels = Epiphyseal fusion (growth stops)

• • ↑Need for independence
  • ↑Sexual awareness/interest
  • Development of sexual personality

• Smooth, Ordered progression of pubertal changes - No matter how long each stage takes, the order in which the changes occur remains the same
• • Breast and Pubic hair in Females
  • Penis and Pubic hair in Males

Question 6

CENTRAL PRECOCIOUS PUBERTY:
What is it dependant on?

How is Consonance affected?

What can it be due to?

What are the signs and symptoms?

How is it treated?

Answer 6

• Gonadotrophins (LH/FSH)
• CONSONANCE IS MAINTAINED
• • Excess GnRH secretion - Idiopathic or Secondary
  • Excess Gonadotrophin secretion - Pituitary tumour
• Accelerated linear growth, Advanced bone ages, ↑Androgen levels
• GnRH analogues to suppress puberty (disrupt pulsatile release) until 11-12yrs if appropriate, Surgery, Radio/Chemotherapy

Question 7

PERIPHERAL PRECOCIOUS (PSEUDO) PUBERTY:
Is it dependant on Gonadotrophins?

How is Consonance affected?

What is it associated with?

Causes:
What is Testotoxicosis?

What can cause an increase in sex steroids?

How does McCune Albright Syndrome cause it?

What can cause an increase in adrenal androgen production?

Answer 7

• No
• NO CONSONANCE
• Suppressed LH/FSH and Increased Oestrogen/Testosterone
• Activating mutation of LH receptor leading to early androgen production by Leydig (M) or Theca (F) cells
• Sex steroid secreting tumour or Exogenous steroids
• Hyperactive signalling pathways and overproduction of Gonadotrophin hormones
• Congenital Adrenal Hyperplasia (CAH)

Question 8

PUBERTAL DELAY:
What is it?

What is Constitutional delay?
→ Who’s it more common in?
→ What is it secondary to?

HYPOgonadotrophic Hypogonadism:
How are LH/FSH affected?

What causes it?

HYPERgonadotrophic Hypogonadism:
How are LH/FSH affected?

What is it caused by?
→ How?

What congenital conditions can cause it?

Answer 8

• No Secondary sexual maturation by:
  o 13yrs in Girls (or absence of Menarche by 18yrs)
  o 14yrs in Boys
• Affects Growth and Puberty
  → 10x more common in Boys
  → Secondary to Chronic illness e.g. DM, CF

• ↓LH, FSH
• • Kallman’s syndrome (GnRH gene migration)
  • Hypopituitarism
  • Impaired Gonadotrophins
  • High doses of Steroid/Opioid medication

• ↑LH, FSH
• Gonadal dysgenesis
  → Low sex steroid levels = Less negative feedback = ↑LH, FSH
• Klinefelter’s (47 XXY), Turners (45 XO)