Overview

• Congenital deficiency of 21-hydroxylase enzyme → underproduction of cortisol and aldosterone + overproduction of androgens from birth.
  • 21-Hydroxylase → converts progesterone into cortisol and aldosterone.
• Autosomal recessive.
• Can also have 11-beta hydroxylase and 17-hydroxylase deficiency.

Making Diagnosis

Clinical Features

• Female patients may present at birth with ambiguous genitalia (virilisation) and enlarged clitoris due to high testosterone levels.

  <aside> 💡 Commonest cause of ambigious genitalia in infants.

  </aside>

• Cortisol + Aldosterone Deficiency → Hyponatreamia + Hyperkalaemia + Hypoglycaemia + Metabolic Acidosis.

  • Leads to poor feeding, vomiting, dehydration, arrhythmias.

• In mild cases may present later in life, with symptoms related to high androgen levels.

Investigations

• Diagnostic → raised 17α-hydroxyprogesterone.

Management Plan

• Cortisol replacement → lifelong hydrocortisone.
• Aldosterone replacement → fludrocortisone.
• Female patients with “virilised” genitals may require corrective surgery.