3 beta hydroxysteroid dehydrogenase deficiency
3 beta hydroxysteroid dehydrogenase deficiency Definition
3-Beta-hydroxysteroid dehydrogenase deficiency (3B HSD) is a very rare disorder of the genes involving steroid biosynthesis. This deficiency results into the decrease on the production of adrenal steroid groups which are inclusive of glucocorticoids, mineralocorticoids, and the sex steroids. A decrease on the secretion of mineralocorticoid would result into various salt wasting degrees in males and females. And for the 46 XY males, a deficiency in androgen would result into ambiguous genitals (the females are seen with enlarged clitoris).
3 beta hydroxysteroid dehydrogenase deficiency Frequency
Looking at the international perspective, individuals with CAH cases are often afflicted with 21-hydroxylase deficiency. This is true in 80-90% of the CAH cases. There are different records for different populations and the list is as follows: 1 in every 5,000-15,000 births or as high as 1 in every 300-700 live births among Yupik Eskimos of Alaska. The secondary type of CAH which is the 11-beta hydroxylase deficiency is recorded at 1 in every 100,000 persons. 3B HSD deficiency is recorded at only less than 1% of all CAH cases.
3 beta hydroxysteroid dehydrogenase deficiency Medical Care
Patients with 3-Beta-hydroxysteroid dehydrogenase deficiency need replacement of glucocorticoids, sex steroids and mineralocorticoids. There are hydrocortisone suppressors that are orally administered. With this suppressors, the ACTH secretion is controlled and there is a significant decrease on the plasma concentrations of DHEA, pregnenolone, and 17-hydroxypregnenolone. Fludrocortisone acetate is also administered orally for the replacement of mineralocorticoids. Those patients that do not have the salt-loss case do not require replacement of mineralocorticoids. Estrogen-progesterone therapies are also good options to replace loss of sex steroids in females while males can undergo the testosterone therapy.
3 beta hydroxysteroid dehydrogenase deficiency Mortality/Morbidity
Since 3B HSD is a requirement to synthesize all 3 adrenal steroids, the absence of this enzyme would automatically result into impairment of steroid production and adrenal insufficiency. Heterogenicity exists mainly because of the deficiency of 3B HSD. The most severe cases could include crises in infancy involving salt-loss. Other than this, the manifestations show much later on in childhood or during adolescence.
3 beta hydroxysteroid dehydrogenase deficiency Pathophysiology
Anatomically speaking, the adrenal gland is divided into three zones which are the: zona glomerulosa, zona fasciculate and the zona reticularis. The zona glomerulosa is the one that produces mineralocorticoids; the zona fasciculata produces the glucocorticoid and the last zone which is the zona reticularis produces the androgens. Mineralocorticoids, glucocorticoids and androgens are the so-called adrenal steroids. 3-Beta-hydroxysteroid dehydrogenase is required to be able to synthesize all the three groups of adrenal steroids. 3B HSD serves as the catalyst to the conversion of the three. Therefore, the absence of the 3B HSD enzyme would impair the production of these adrenal steroids. Adrenal insufficiency would result after cortisol and aldosterone deficiencies while reduction of sex steroid would result into ambiguous genitals.