230 likes | 1.22k Views
Congenital Adrenal Hyperplasia. a group of autosomal recessive disorders resulting from the deficiency of one of the five enzymes required for the synthesis of cortisol in the adrenal cortex.
E N D
Congenital Adrenal Hyperplasia • a group of autosomalrecessive disorders resulting from the deficiency of one of the five enzymes required for the synthesis of cortisol in the adrenal cortex. • The most frequent is steroid 21-hydroxylase deficiency, accounting for more than 90 percent of cases.
Clinical Manifestations • classic 21-hydroxylase deficiency • Sallt-wasting type-defect in aldosterone biosynthesis (salt-wasting type) • Simple virilizing type-apparently normal aldosterone • non-classic 21-hydroxylase deficiency • that may be asymptomatic or associated with signs of postnatal androgen excess
1) salt wasting • failure to synthesize aldosterone, progesterone and 17-hydroxyprogesterone act as mineralocorticoid antagonist • - excessive renal sodium = hypovolemia, hyperreninemia, hyperkalemia • -cortisoldeficiency contributes to poor cardiac function, poor vascular response to catecholamines, decreased production of cathecolamines , a decreased GFR, and increased ADH • may ultimately lead hyponatremic dehydration and shock
2) ambiguous genitalia • Girls: large clitoris, rugated and partially fused labia majora, and a common urogenital sinus in place of a separate urethra and vagina. • Boys: no overt signs of the disease except variable and subtle hyperpigmentation and penile enlargement
3) postnatal virilization • long-term exposure to high levels of sex hormones promotes rapid somatic growth (predominantly an androgen effect) and advanced skeletal age, which leads to premature epiphysealfusion (predominantly an effect of extragonadalaromatization of androgens to estrogens) • Pubic & axillary hair, clitoral and penile growth may continue in girls. • Activation of HPO-axis, causing centrally mediated precocious puberty
4) linear growth • height tends to be below the population mean • premature epiphyseal closure • latter resulting in glucocorticoid-induced inhibition of the growth
5) reproductive function • oligomenorrhea and amenorrhea may develop in adolescence • problems related to psychosocial adjustment • 80 percent of women with simple virilizingdisease and approximately 60 percent of those with the severe salt-wasting form are fertile • affected men have fewer problems with reproductive function, • specifically gonadalfunction (normal sperm counts), though some may develop testicular adrenal rests