Congenital adrenal hyperplasia in children

Congenital adrenal hyperplasia is also called adrenal genital syndrome or adrenal abnormality. Mainly due to the deficiency of the enzymes necessary for the adrenocortical hormone biosynthesis process, the corticosteroid synthesis is abnormal. In most cases, the adrenal glands secrete insufficient glucosamine and salt hormones and too much androgenic hormones, so clinically there are varying degrees of adrenal insufficiency, accompanied by virilization of girls, and boys with precocious puberty, and hyponatremia Or hypertension and other symptoms. According to the types of defective enzymes, they can be divided into 5 categories: ① 2l-hydroxylase (CYP21) deficiency, which is divided into typical subtypes such as salt loss, virilization and atypical; ② 11β-hydroxylase (CYP11β) Defects can be divided into types Ⅰ and Ⅱ; ③ 3β-hydroxysteroid dehydrogenase (3β-HSD) deficiency; ④ 17α-hydroxylase (CYP17) deficiency, with or without 17,20-chain enzyme (17,20LD) deficiency; ⑤ cholesterol carbon chain enzyme deficiency. Clinically, 21-hydroxylase deficiency is the most common, accounting for more than 90%, and its incidence is about 1/4500 newborns, of which about 75% are salt-losing, followed by β-hydroxylase deficiency, which accounts for about From 5% to 8%, the incidence is about 1/5000 to 7000 newborns. Other types are rare.