Inborn dysfunction of bark of adrenal glands
Contents:
Description:
Inborn dysfunction of bark of adrenal glands (adrenogenital syndrome) - group autosomal рецессивно the inherited disturbances of synthesis of corticosteroids. More than 90% of all cases of an adrenogenital syndrome are caused by deficit of 21 hydroxylases.
Symptoms of Inborn dysfunction of bark of adrenal glands:
Solteryayushchy form of deficit of 21 hydroxylases:
1. Surplus of androgens, since early stages of fetation, at newborn girls causes an intersexual structure of outside genitalias (a female pseudohermaphroditism). Expressiveness of changes varies from a simple hypertrophy of a clitoris to a full masculinization of genitalias: a penisoobrazny clitoris with an urethra opening ekstenziya on its head. A structure of internal genitalias at fruits with a female genotype at an adrenogenital syndrome always normal. At boys increase in the sizes of a penis and a hyperpegmentation of a scrotum are noted. In the absence of treatment in the post-natal period there is a bystry progressing of virilescence. Regions of growth of bones therefore at adult patients low-tallness is, as a rule, noted are quickly closed. At girls in the absence of treatment primary amenorrhea connected with suppression of pituitary and ovarian system surplus of androgens is defined.
2. Adrenal insufficiency (deficit of Aldosteronum and cortisol) is shown by such symptoms as sluggish suction, vomiting, dehydration, a metabolic acidosis, the accruing adynamia. Electrolytic changes and dehydration, characteristic of adrenal insufficiency, develop. The specified symptoms in most cases demonstrate between the 2nd and 3rd week after the child's birth. One of manifestations of deficit of glucocorticoids is the progressing hyperpegmentation.
The simple virilny form of deficit of 21 hydroxylases develops owing to moderate deficit of enzyme, at the same time the solteryayushchy syndrome (adrenal insufficiency) does not develop. But the expressed surplus of androgens, since the pre-natal period, causes the virilescence manifestations described above.
Nonclassical (post-pubertal) form of deficit of 21 hydroxylases. Prenatal virilescence of outside genitalias and signs of adrenal insufficiency are absent. The clinical picture considerably varies. Most often this form of a syndrome is diagnosed for women of reproductive age at purposeful inspection concerning an oligomenorrhea (50% of patients), infertility, a hirsutism (82%), an acne (25%). In some cases any clinical manifestations and decrease in fertility are practically absent.
Reasons of Inborn dysfunction of bark of adrenal glands:
The gene of enzyme 21 of a hydroxylase is located on a short limb 6. There are two genes - the active gene of CYP21-B coding 21 hydroxylases, and an inactive pseudo-gene of CYP21-A. These genes are considerably homologous. Existence near the coding gene of the homologous DNA sequence often leads to disturbances of pairing in meiosis and as a result of it is to conversion of genes (movement of a fragment of an active gene of a pseudo-gene), or to deletion of a part of a semantic gene. In both cases function of an active gene is broken. On a chromosome 6 near genes of CYP21 there are genes of HLA which are inherited kodominantno therefore at all homozygous sibs the identical HLA haplotype will be defined.
Treatment of Inborn dysfunction of bark of adrenal glands:
At classical forms to children the tableted hydrocortisone in a daily dose of 15-20 mg/sq.m of a body surface or Prednisolonum of 5 mg/sq.m is appointed. The dose breaks into 2 receptions: 1/3 Doses in the morning, 2/3 doses for the night for the maximum suppression of products of AKTG a hypophysis. At a solteryayushchy form purpose of a fludrokortizon (50-200 mkg/days) is in addition necessary. At serious associated diseases and operative measures the dose of glucocorticoids needs to be increased. At late diagnosis of a virilny form of an adrenogenital syndrome of streets with genetically female surgical interventions can be necessary for plastics of outside genitalias. The post-pubertal (nonclassical) form of an adrenogenital syndrome owing to deficit of 21 hydroxylases demands therapy only in the presence of the expressed cosmetic problems (a hirsutism, an acne) or at decrease in fertility.
