Steroid 21-hydroxylase deficiency is the most common cause of congenital adrenal hyperplasia. Its incidence in Finland is about 1:15 000 in newborns. The essential features are defects (often partial) in cortisol biosynthesis with resulting elevated ACTH levels and consequent disorders in the production of other adrenal steroids, notably androgens and mineralocorticoids. The production of aldosterone is low, whereas androgens are produced in excess. Severe forms of the disease lead to virilization of girls and to critical salt loss in girls or boys. Milder forms of the disease can cause accelerated growth and early maturation in childhood. In adult women, the mild form of the disease may cause infertility, irregular menstrual cycle, acne and hirsutism. The disease is inherited recessively, and therefore patients with 21-hydroxylase deficiency have inherited the mutation from both parents. In Finland, three founder mutations explain the majority of the disease.
The analysis is performed from a whole blood sample (EDTA). Instructions for storage and sending the sample as well as prices for DNA screening are given in the request form. The report and interpretation of the results are mailed to the address given in the order 6-8 weeks after the arrival of the blood sample.