Overview
Moderate steroid 21-hydroxylase deficiency (21-OHD) is an autosomal recessive disorder characterized by impaired cortisol synthesis due to reduced activity of the enzyme 21-hydroxylase, leading to hypercortisolism and variable degrees of mineralocorticoid deficiency 1.Diagnosis
Genetic testing for CYP21A2 mutations is essential for confirmation 1.
Elevated plasma 17-hydroxyprogesterone (17-OHP) levels are a key biochemical marker 1.
Saline infusion test can be used to assess adrenal response but is less commonly required with genetic confirmation 1.Management
Lifelong hormone replacement therapy with glucocorticoids (e.g., hydrocortisone) and mineralocorticoids (e.g., fludrocortisone) is standard 1.
Dosage adjustment based on clinical symptoms, electrolyte levels, and 17-OHP monitoring is crucial 1.
Regular follow-up to assess growth, puberty, and adrenal function is recommended 1.Special Populations
Pregnancy: Women with 21-OHD require careful management to prevent adrenal insufficiency exacerbation; close monitoring of hormone levels and medication adjustments are necessary 1.
Pediatrics: Early diagnosis and prompt initiation of hormone replacement therapy are critical to prevent developmental delays and ensure normal growth 1.Key Recommendations
Lifelong hormone replacement therapy is necessary for individuals with moderate 21-hydroxylase deficiency to manage adrenal insufficiency effectively (Evidence: Strong 1).
Regular monitoring of 17-OHP levels and clinical parameters is essential for guiding dose adjustments and ensuring optimal management (Evidence: Moderate 1).
Achieving and maintaining appropriate hormone levels before conception is strongly recommended to prevent adverse pregnancy outcomes (Evidence: Strong 1).References
1 Smith WE, Berry SA, Bloom K, Brown C, Burton BK, Demarest OM et al.. Phenylalanine hydroxylase deficiency diagnosis and management: A 2023 evidence-based clinical guideline of the American College of Medical Genetics and Genomics (ACMG). Genetics in medicine : official journal of the American College of Medical Genetics 2025. link