Endocrine: Congenital Adrenal Hyperplasia

21α-Hydroxylase Deficiency

Basics

  • Most Common Cause of Congenital Adrenal Hyperplasia
  • Deficiency:
    • Impaired Conversion of Progesterone to 11-Deoxycorticosterone
    • Impaired Conversion of 17-Hydroxyprogesterone to 11-Deoxycortisol
  • Effects: Mn
    • Decreased Mineralocorticoid Production
    • Decreased Cortisol Production
    • Increased Androgen Production

Presentation

  • Salt-Wasting:
    • Hyponatremia
    • Hyperkalemia
    • Increased Renin
  • Hypocortisolism:
    • Nausea & Vomiting
    • Diarrhea
    • Adrenal Crisis
    • Hypovolemia & Shock
  • Virilization:
    • Precocious Puberty
    • Masculinization
    • Ambiguous Genitalia in Females
      • Clitoral Enlargement
      • Labial Fusion
    • Infertility
    • Hirsutism
    • Acne

Diagnosis

  • Diagnosis: Elevated Plasma 17-Hydroxyprogesterone & Low Cortisol
  • May Need ACTH Stimulation Test if Equivocal

Treatment

  • Primary Treatment: Corticosteroids & Mineralocorticoids (Fludrocortisone)
  • May Require Genitoplasty Reconstructive Surgery

Adrenal Hormone Synthesis 1

11β-Hydroxylase Deficiency

Basics

  • Deficiency:
    • Impaired Conversion of 11-Deoxycorticosterone to Corticosterone
    • Impaired Conversion of 11-Deoxycortisol to Cortisol
  • Effects: Mn
    • Increased 11-Deoxycorticosterone Acts as a Strong Mineralocorticoid Despite Decreased Aldosterone Production
    • Decreased Cortisol Production
    • Increased Androgen Production

Presentation

  • Salt-Saving:
    • Hypertension
    • Hypokalemia
  • Hypocortisolism:
    • Nausea & Vomiting
    • Diarrhea
    • Adrenal Crisis
    • Hypovolemia & Shock
  • Virilization:
    • Precocious Puberty
    • Masculinization
    • Ambiguous Genitalia in Females
      • Clitoral Enlargement
      • Labial Fusion
    • Infertility
    • Hirsutism
    • Acne

Diagnosis

  • Diagnosis: Elevated Plasma 11-Deoxycortisol & Low Cortisol

Treatment

  • Primary Treatment: Corticosteroids
  • Mineralocorticoid Receptor Antagonists (Spironolactone & Eplerenone) If Needed for Hypertension
  • May Require Genitoplasty Reconstructive Surgery

Adrenal Hormone Synthesis 1

17α-Hydroxylase Deficiency

Basics

  • Deficiency:
    • Impaired Conversion of Pregnenolone to 17-Hydroxypregnenolone
    • Impaired Conversion of Progesterone to 17-Hydroxyprogesterone
  • Effects: Mn
    • Increased Mineralocorticoid Production
    • Decreased Cortisol Production
    • Decreased Androgen Production

Presentation

  • Salt-Saving:
    • Hypertension
    • Hypokalemia
  • Hypocortisolism:
    • Nausea & Vomiting
    • Diarrhea
    • Adrenal Crisis
    • Hypovolemia & Shock
  • Virilization:
    • Primary Amenorrhea
    • Absence of Secondary Sexual Characteristics
    • Minimal Body Hair
    • Ambiguous Genitalia

Diagnosis

  • Diagnosis: Elevated Plasma 11-Deoxycorticosterone & Corticosterone with Low Cortisol & Androgens

Treatment

  • Primary Treatment: Corticosteroids
  • Mineralocorticoid Receptor Antagonists (Spironolactone & Eplerenone) If Needed for Hypertension
  • Sex Hormone Supplementation (Estrogen or Testosterone)
  • May Require Genitoplasty Reconstructive Surgery

Adrenal Hormone Synthesis 1

Mnemonics

Effects of Congenital Adrenal Hyperplasia

  • To Remember the Effects: Write “A-T”; Then Write the Associated Number Underneath
    • A-Aldosterone; T-Testosterone
    • A Before T: “BP Goes Up Before Having Sex”
  • 1 (Up Arrow) Increases & Other Numbers Decrease

References

  1. Colo M. Wikimedia Commons. (License: CC BY-SA-3.0)