Adrenal Hyperplasia, Congenital
Present from birth, a rare genetic disorder, in which an enzyme (a protein that acts as a catalyst) defect blocks the production of corticosteroid hormones from the adrenal glands.
The enzyme block results in production of very high amounts of androgens (male sex hormones), which can cause abnormal genital development in an affected foetus. In females, these androgens cause growth of the clitoris and some fusion of the outer lips of the vulva, resulting in genital ambiguity. Some affected males have an enlarged penis, which may be present at birth or may develop later.
Other effects of the enzyme defect include hypoglycaemia (low blood sugar levels), hypotension (low blood pressure), weight loss and dehydration. Hyperplasia (enlargement) of the adrenal gland occurs due to excessive secretion of the hormone ACTH, which is a result of inadequate production of hydrocortisone. In skin creases and around the nipples, excessive skin pigmentation may occur.
In extreme cases, congenital adrenal hyperplasia is apparent soon after birth. In milder cases, symptoms can appear later, occasionally producing premature puberty in boys and delayed menstruation, potential infertility and hirsutism (excessive hairiness) in girls.
Diagnosis and treatment
By measuring corticosteroid hormones in the blood and urine a diagnosis is confirmed. To verify that there is no tumour of the adrenal glands ultrasound scanning may be carried out.
Treatment of congenital adrenal hyperplasia is with hormone replacement. Hormone replacement therapy does have strong side effects that can create other health issues in an individual. Normal sexual development and fertility generally follow if the treatment is started early.