CausesBy Mayo Clinic staff
Congenital adrenal hyperplasia affects your adrenal glands, a pair of walnut-sized organs located above your kidneys.
Inherited defect affects cortisol production
The cause of congenital adrenal hyperplasia is an inherited genetic defect that limits production of one of the many enzymes the adrenal glands use to make cortisol. The enzyme most commonly lacking in congenital adrenal hyperplasia is 21-hydroxylase. Congenital adrenal hyperplasia may sometimes be called 21-hydroxylase deficiency. Signs and symptoms of congenital adrenal hyperplasia are worst when the enzyme deficiency is severe.
Most of the problems caused by classic congenital adrenal hyperplasia are related to a lack of cortisol, which plays an important role in regulating your blood pressure, maintaining blood sugar and energy levels, and protecting your body against stress.
A child with classic congenital adrenal hyperplasia may also experience:
- A lack in the adrenal glands' production of aldosterone. This can lead to low blood pressure, lower sodium level and higher potassium level. Sodium and potassium normally work together to help maintain the right balance of fluids in your body, transmit nerve impulses, and contract and relax your muscles.
- Excess production of the male sex hormones (androgens such as testosterone). This can result in short height, early puberty in boys, abnormal genital development in girls and severe acne. Signs and symptoms may vary, depending on which specific gene is defective.
The condition is passed along in an inheritance pattern called autosomal recessive. Children who have the disorder have two parents who either have the condition themselves or who are both carriers of the genetic mutation that causes the condition.
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