Inherited group of disorders characterised by a deficiency in one of the enzymes necessary for cortisol synthesis
Aetiology
90% due to an autosomal recessive 21⍺-hydroxylase deficiency
Pathophysiology
21⍺-hydroxylase deficiency prevents the production of aldosterone and cortisol
Increased volume of precursors will be diverted into the androgen pathway → increased testosterone and dihydrotesterone
Reduced cortisol stimulates ACTH release and cortical hyperplasia
Other enzyme deficiencies will result in varied clinical features depending on the pathway affected (e.g. adrenal insufficiency with no signs of reduced aldosterone or vice versa)
Clinical features
Classic CAH
Presents at birth or shortly after
Genital ambiguity (virilisation) in females
Adrenal failure - collapse, hypotension, hypoglycaemia, poor weight gain