Congenital Adrenal Hyperplasia (CAH)

• autosomal recessive traits.
• The most common enzyme defect is 21-hydroxylase deficiency. 
• 11β-hydroxylase & 17-hydroxylasedeficiency → hypertension due to excess production of 11-deoxycorticosterone having mineralocorticoid activity

Clinical features:

• Ambiguous genitalia in girls (androgen excess)
• Amenorrhoea, hirsutism, pigmentation (ACTH), 
• Hypotension, hypertension
• Androgen excess→ precocious pseudopuberty, which is distinguished from ‘true’ precocious puberty by low gonadotrophins.

Investigation

Management:

• Corticosteroid replacement
  • reverse rhythm to suppress early morning ACTH (steroid given at night)

• Late-onset 21-hydroxylase deficiency: 
  • corticosteroid may not be needed. 
  • For hirsutism: anti-androgen therapy 

Follow up:

• Clinical: 
  • menstrual cycle, hirsutism, 
  • weight gain, blood pressure

• biochemical profiles 
  • plasma renin, 
  • 17-OH-progesterone,
  • testosterone levels