Congenital adrenal hyperplasia due to 17 alpha-hydroxylase deficiency

Overview of Congenital adrenal hyperplasia due to 17 alpha-hydroxylase deficiency

Congenital adrenal hyperplasia due to 17 alpha-hydroxylase deficiency
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Synonyms	N/A
Pronounce	N/A
Specialty	N/A
Symptoms	Hypertension, hypokalemia, sexual infantilism
Complications	Infertility, adrenal crisis
Onset	Congenital
Duration	Lifelong
Types	N/A
Causes	Genetic mutation in CYP17A1
Risks	N/A
Diagnosis	Hormonal assays, genetic testing
Differential diagnosis	N/A
Prevention	N/A
Treatment	Hormone replacement therapy
Medication	N/A
Prognosis	N/A
Frequency	Rare
Deaths	N/A

Congenital adrenal hyperplasia due to 17 alpha-hydroxylase deficiency is a rare form of congenital adrenal hyperplasia (CAH) characterized by a deficiency in the enzyme 17α-hydroxylase, which is crucial for the production of glucocorticoids and sex steroids. This condition leads to a unique set of clinical features, including hypertension, hypokalemia, and sexual infantilism.

Pathophysiology

The enzyme 17α-hydroxylase, encoded by the CYP17A1 gene, is responsible for the conversion of pregnenolone and progesterone into their 17-hydroxylated products, which are precursors for the synthesis of cortisol and sex steroids. In 17α-hydroxylase deficiency, this conversion is impaired, leading to:

• Decreased production of cortisol and sex hormones (androgens and estrogens).
• Accumulation of mineralocorticoid precursors, resulting in excess production of aldosterone.

The excess aldosterone causes hypertension and hypokalemia, while the lack of sex steroids results in underdeveloped secondary sexual characteristics.

Clinical Presentation

Patients with 17α-hydroxylase deficiency typically present with:

• Hypertension: Due to excess mineralocorticoid activity.
• Hypokalemia: Resulting from increased renal excretion of potassium.
• Sexual Infantilism: Lack of sexual development due to deficiency of sex steroids.
• Ambiguous genitalia: In genetic males (46,XY), due to lack of androgen production.
• Primary amenorrhea: In genetic females (46,XX), due to lack of estrogen production.

Diagnosis

Diagnosis is based on clinical features and confirmed by:

• Hormonal assays: Elevated levels of 11-deoxycorticosterone and corticosterone, low levels of cortisol and sex steroids.
• Genetic testing: Identification of mutations in the CYP17A1 gene.

Treatment

Management of 17α-hydroxylase deficiency involves:

• Glucocorticoid replacement therapy: To suppress excess ACTH and reduce mineralocorticoid production.
• Sex hormone replacement therapy: To induce secondary sexual characteristics and manage sexual infantilism.
• Antihypertensive medications: To control blood pressure if necessary.

Prognosis

With appropriate treatment, individuals with 17α-hydroxylase deficiency can lead normal lives, although they may face challenges related to infertility and the need for lifelong hormone replacement therapy.

Also see

• Congenital adrenal hyperplasia
• CYP17A1
• Hypertension
• Hypokalemia
• Hormone replacement therapy