17a-Hydroxylase deficiency

Serum steroid hormonal profiles by reversed-phased liquid chromatography in patients with 17a-hydroxylase deficiency. (158)... 

Honour JW, Tourniaire J, Biglieri EG, Shackleton CHL (1978) Urinary steroid excretion in 17a-hydroxylase deficiency. J Steroid Biochem 9 495-505... 

Why do patients with 21-hydroxylase deficiency exhibit low blood pressure whereas those with 17a-hydroxylase deficiency exhibit high blood pressure ... 

When the condition of 17a-hydroxylase deficiency occurs, the production of cortisol and sex steroids (except for progesterone) is impaired and the production of miner-alocorticoids increased (see Figure 51-4, Chapter 51). With tliis deficiency, plasma concentrations of corticosterone, 11 - deoxycorticosterone, progesterone, and pregnenolone are elevated. Boys exhibit pseudohermaphroditism and deficiency in development of secondary sex characteristics. 

A 17a-hydroxylase deficiency is a rare form of CAH that is associated with delayed puberty, primary amenorrhea, and hypertension. These patients have a 46 XX karyotype with elevated gonadotropins, low sex steroids, hypertension, and hypokalemia (see Chapter 51). ... 

Monno, S., Y. Mizushima, N. Toyoda, T. Kashii, and M. Kobayashi (1997). A new variant of the cytochrome P450cl7 (CYP17) gene mutation in three patients with 17a-hydroxylase deficiency. Ann. Hunt. Genet. 61, 275-279. 

Monno, S., H. Ogawa, T. Date, M. Fujioka, W.L. Miller, and M. Kobayashi (1993). Mutation of histidine 373 to leucine in cytochrome P450cl7 causes 17a-hydroxylase deficiency. J. Biol. Chem. 268, 25811-25817. 

HD 21 -Hydroxylase deficiency 5PT 5-pregnene-3/ ,17a,20a-triol, 160HDHEA 16a-hydroxyDHEA, 17HP 17a-hydroxy-pregnanolone, d days, Fs cortisol metabolites, m months, yrs years, Pat patient, PTONE pregnanetriolone... 

Joannou GE (1981) Identification of 15/5-hydroxylated C21 Steroids in the neo-natal period the role of 3a,15/),17a-trihydroxy-5/ -pregnan-20-one in the perinatal diagnosis of congenital adrenal hyperplasia (CAH) due to a 21-hydroxylase deficiency. J Steroid Biochem 14 901-912... 

Bilateral adrenal hyperplasia Secondary hyperaldosteronism Hyperreninemic hyperaldosteronism (hypertension) Congenital adrenal hyperplasia (due to adrenal enzyme deficiencies in cortisol production [11 3- or 17a-hydroxylase])... 

A deficiency of ll -hydroxylase is the second most common form of CAH, with an incidence of 1 per 100,000 births, and is associated with manifestations of virilization, elevated concentrations of plasma androstenedione and DHEA-S, and hypertension. The mineralocorticoid-induced hypertension is caused by an elevation of DOC 11-deoxycortisol concentrations are markedly raised in subjects with this enzyme defect,The major distinguishing characteristic of this disorder from 21-hydroxylase deficiency, besides the elevated plasma concentrations of 11-deoxycortisol, is hypertension elicited by the salt retention caused by increased concentrations of DOC, A deficiency of 3 -hydroxysteroid dehydrogenase-isomerase has been reported and leads to an elevation in the ratio of 17a-hydroxypregnenolone to that of 17a-hydroxyprogesterone and to an increased ratio of DHEA to androstenedione. In severe forms of this rare disorder, female infants have pseudohermaphroditism, and male infants present with incomplete masculinization. Patients with this disorder usually present in early infancy with complete adrenal insufficiency including salt wasting. A late-onset form has also been reported in patients with premature pubarche with hirsutism, acne, and menstrual irregularities. The... 

Deficiency of 17a-hydroxylase (CYP17), the enzyme required for formation of cortisol and androgens, also causes congenital adrenal hyperplasia. The genetic defect also affects the gonads, which consequently cannot synthesize androgens or estrogens. Thus, the anterior pituitary increases its output of ACTH, LH, and FSH. 

Gonadotropin and gonadotropin-receptor abnormalities signal defects Enzyme deficiencies cho/esfero/c/esmo/ase, 17a-hydroxylase, 17, 20-desmolase Galactosemia... 

This can be due to defects in several enzyme systems required for the formation of cortisol (Fig. 8), but in all cases the inadequate level of cortisol in the blood causes corticotropin to be secreted by the pituitary in increasing amount this in turn causes hyperplasia of the adrenal glands with overproduction of those steroids not affected by the enzyme block. The most common deficiency is in 21-hydroxylase, but deficiencies have also been reported in infants and children of 3j8-HSD, lljff-hydroxy-lase, and cholesterol desmolase, and in older infants of 17a-hydroxylase (N4). 

Imai, X, H. Globerman, J.M. Gertner, N. Kagawa, and M.R. Waterman (1993). Expression and purification of functional human 17a-hydroxy-lase/17,20-lyase (P450cl7) in Escherichia coli. Use of this system for study of a novel form of combined 17a-hydroxylase/17,20-lyase deficiency. J Biol. Chem. 268, 19681-19689. 

P. Ferreira, E.R. Simpson, and J.S. Winter (1989). Identification of a common molecular basis for combined 17a-hydroxylase/17,20-lyase deficiency in two Mennonite families. Hum. Genet. 82, 285-286. 

K. Kangawa, and S. Matsukura (1997). A 5 -splice site mutation in the cytochrome P450 steroid 17a-hydroxylase gene in 17a-hydroxy-lase deficiency. J. Clin. Endocrinol. Metab. 82, 1934-1938. 

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