21-hydroxylase deficiency
Pronunciation: twenty-one hye-DROK-see-lase
Most common form of congenital adrenal hyperplasia caused by mutations in the CYP21A2 gene affecting cortisol and aldosterone production.
Full Definition
The most prevalent form of congenital adrenal hyperplasia, accounting for approximately 95% of all CAH cases. The condition results from deficiency of the 21-hydroxylase enzyme, encoded by the CYP21A2 gene, which is essential for cortisol and aldosterone synthesis. The deficiency leads to accumulation of precursor hormones that are shunted into androgen production pathways, causing virilization. Clinical presentations range from classic salt-wasting and simple virilizing forms to non-classic (late-onset) forms with milder symptoms. The condition requires lifelong hormone replacement therapy and careful monitoring.
Usage
Usage note: Use the number format '21-' rather than spelling out 'twenty-one' in medical documentation.
In Context
- "Genetic testing confirmed 21-hydroxylase deficiency with two pathogenic mutations." — Genetic counseling report
- "The patient's 21-hydroxylase deficiency requires stress-dose steroid coverage during surgery." — Preoperative assessment