Congenital dysfunction of the adrenal cortex on the background of 11β-hydroxylase deficiency

Abstract

Congenital adrenal dysfunction (CHD) is a variant of hereditary fermentopathies that lead to a violation of the synthesis of cortisol in the adrenal cortex. Late diagnosis of this pathology significantly impairs the quality of life of patients, and in some cases can lead to fatal consequences. The most common form of CHD, occurring in more than 90% of cases, is due to a deficiency of 21-hydroxylase, which is responsible for the synthesis of deoxycorticosterone and 11-deoxycortisol. The prevalence of this form is 1:10,000 to 1:20,000 newborns in the world, in Russia — 1:9500. In second place is the deficiency of 11β-hydroxylase (hypertonic form of HCHD), which affects the synthesis of cortisol. This form of the disease occurs in about 1:100,000 newborns in the world, and in Russia the prevalence of this form is unknown [1].The cause of any form of CHD is mutations in the genes responsible for the synthesis of enzymes or transport proteins involved in the synthesis of cortisol. 11β-hydroxylase is synthesized in the zona fasciculata of the adrenal cortex and is regulated by adrenocorticotropic hormone by a negative feedback mechanism. 11β-hydroxylase deficiency (hypertonic form of HCHD) develops as a result of mutations in the CYP11B gene located on chromosome 8. This mutation blocks the enzymatic conversion of 11-deoxycortisol to cortisol, as well as deoxycorticosterone (DOC) to corticosterone, leading to the accumulation of DOC, which has mineralocorticoid activity. It is the excess of deoxycorticosterone that causes an increase.In 21-hydroxylase deficiency, the clinical picture is primary adrenal insufficiency (deficiency of glucoand mineralocorticoids). The clinical picture of mineralocorticoid deficiency includes salt loss syndrome: arterial hypotension, tachycardia, adynamia, fibrillary muscle twitching, dryness and decreased skin turgor, cyanosis and marbling of the skin. Glucocorticoid deficiency is manifested by muscle weakness, fatigue, hyperpigmentation of the skin. With a deficiency of 11β-hydroxylase, due to an increase in the level of deoxycorticosterone, there is no deficiency of mineralocorticoid activity, on the contrary, against the background of clinical signs of glucocorticoid insufficiency, an increase in blood pressure may be observed. Hyperandrogenism is characteristic of both forms of CHD. Symptoms of hyperandrogenism in females: virilization of the external genitalia, amenorrhea, severe alopecia and hirsutism. In undiagnosed cases of CHD, patients with a female karyotype have a male phenotype.