Congenital Adrenal Hyperplasia (CAH)

Endocrinology / Pediatrics

Overview

Definition

A group of autosomal recessive disorders characterized by enzyme deficiencies in the cortisol synthesis pathway, most commonly 21-hydroxylase deficiency, leading to excess androgen production.

Epidemiology

Classic form occurs in ~1 in 15,000 live births. Screened at birth in many countries.

Etiology & Risk Factors

  • Autosomal recessive genetic mutation in the CYP21A2 gene (21-hydroxylase deficiency in >90% of cases)

Clinical Symptoms

  • Classic Salt-Wasting (neonatal crisis: vomiting, dehydration, hyponatremia, hyperkalemia, shock)
  • Ambiguous genitalia in newborn females
  • Precocious puberty, rapid growth, and short stature in childhood

Clinical Approach

Diagnosis

  • Elevated serum 17-hydroxyprogesterone (17-OHP)
  • Hyponatremia, hyperkalemia, and elevated renin in salt-wasting form

Management

  • Glucocorticoid replacement (Hydrocortisone/Fludrocortisone to replace cortisol/aldosterone and suppress ACTH)
  • Stress dosing during illness

Complications

  • Life-threatening Adrenal Crisis
  • Infertility
  • Virilization in females