The molecular basis of 17 alpha-hydroxylase/17,20-lyase deficiency syndrome in a 14-yr-old 46,XY Italian patient was investigated by amplification, subcloning, and sequencing of specific exonic sequences from genomic DNA samples. A homozygous mutation, consisting of a 518-basepair (bp) deletion combined with a 469-bp insertion, was identified in the CYP17 gene of the patient. The deletion spans much of exon II, the whole intron 2, and a portion of exon III. A part (156 bp) of the inserted sequence shows 95.5% identity to the nuclear antigen-binding site on Marek disease virus DNA and sequences found in rearranged mitochondrial DNA of rat hepatoma cells. A similar degree of sequence identity (99%) was also found between the above sequences and part of the lac operon of E. coli. The inserted sequence is lacking the BamHI site in intron 2 of CYP17 and contains an in-frame stop codon (TAA). Thus, the mutated gene encodes a truncated nonfunctional steroid hydroxylase, giving rise to symptoms associated with complete combined 17 alpha-hydroxylase/17,20-lyase deficiency. The family history revealed that the patient is the child of a consanguineous marriage and has two genotypically and phenotypically female sisters also suffering from symptoms of the disease. Investigation of genomic DNA from these sisters revealed that in each case both CYP17 alleles contained the same mutation. On the other hand, the parents were found to be heterozygous for this mutation. The insertion could not be found in DNA from normal individuals or in the CYP17 gene of other Italian patients with the 17 alpha-hydroxylase deficiency syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)
We have studied a family (12 members) with 3 patients (2 adult females and 1 pubertal-aged genotypic male) affected by congenital adrenal hyperplasia due to 17-alpha-hydroxylase deficiency, all of whom presented as phenotypically female subjects with lack of sexual development and with hypokalemic hypertension. The baseline hormonal pattern revealed low glucocorticoid levels (17-hydroxyprogesterone, plasma and urinary cortisol, cortisol secretion rate), as well as androgen (testosterone and dehydroepiandrosterone sulfate) and estrogen (17-beta-estradiol) levels, since the defect is present at both adrenal and gonadal levels. As a consequence ACTH, LH, and FSH concentrations were high. Otherwise steroids not requiring 17-alpha-hydroxylation, such as deoxycorticosterone, corticosterone and their 18-hydroxylated compounds, were secreted in excess with the exception of aldosterone whose levels were undetectable; baseline plasma renin activity levels were suppressed. Short-term dexamethasone treatment normalized potassium and reduced blood pressure and the abnormal mineralocorticoid levels. During chronic ACTH suppression with low doses of glucocorticoids (8 years), electrolyte disturbances were corrected, blood pressure was normalized in 2 cases but only reduced in the third; plasma renin activity returned to normal range within four years in all the patients, while urinary aldosterone was normalized only after 8 years of therapy and became partially responsive to posture, ACTH, angiotensin II, and furosemide. The other mineralocorticoids were reduced but remained above the normal range. The HLA-genotyping in all the family members revealed that the gene responsible for 17-alpha-hydroxylase deficiency was not linked to the HLA system. Measurement of plasma steroids (deoxycorticosterone, corticosterone, aldosterone) in this family revealed that the heterozygotes were different from the control population only in their ACTH-stimulated corticosterone levels.
Ketoconazole is an orally active antimycotic agent and a potent inhibitor of gonadal and adrenal steroidogenesis. As inhibitor of steroid production, it has been employed in Cushing's syndrome, prostatic cancer and precocious puberty due to autonomous Leydig-cell hyperfunction. By virtue of its selective action on androgen synthesis at low doses by inhibition of C17-20 lyase, this drug could be of potential therapeutic utility in hirsutism. We evaluated the hormonal and clinical effects of a low-dose regimen (400 mg/day) for 3 months in 16 women with a spectrum of disorders from idiopathic hirsutism to polycystic ovary syndrome. Four of them completed 6-month treatment. At 3 months, DHEA-S decreased from 9.9 +/- 1.0 (mean +/- SE) to 6.9 +/- 1.0 mumol/L (p less than 0.01), androstenedione from 13.3 +/- 1.5 to 8.3 +/- 1.3 nmol/L (p less than 0.005), and testosterone from 4.2 +/- 0.4 to 3.1 +/- 0.4 nmol/L (p less than 0.05). No significant changes were observed in LH, FSH, prolactin and estradiol levels. In patients treated for 6 months, androgens were within normal limits at the end of the study. Eleven out of 16 women (about 70%) reported some improvement in their hirsutism. There was a significant decrease in Ferriman-Gallwey's score (p less than 0.001) and mean hair-shaft diameter (p less than 0.001). The patients treated for 6 months showed a further improvement. Pelvic ultrasonography, when repeated (n = 8), was either unchanged or improved. Side effects (polymenorrhea, gastrointestinal reaction, somnolence) were generally mild and transient. Of 20 women who entered the study the dropout rate was 20% (n = 4).(ABSTRACT TRUNCATED AT 250 WORDS)
Primary aldosteronism is the principal disorder of the zona glomerulosa, and a number of subsets have been identified: unilateral adenoma, bilateral micro- or macronodular hyperplasia (idiopathic aldosteronism) primary hyperplasia, and aldosterone-producing carcinoma, either adrenal or ectopic. The diagnostic criteria for a correct differential diagnosis of these subsets are now quite reliable, and our experience is presented in detail. Unfortunately, the pathogenesis of most of these forms is still poorly recognized and requires further investigation. An extreme sensitivity to angiotensin II is present in patients with idiopathic aldosteronism, and a role of adrenal renin is now being advocated. A peculiar form of hyperaldosteronism is the glucocorticoid-remediable subtype. An unusual sensitivity of aldosterone to ACTH is present in this form. The qualitative biochemical abnormality in this disorder consists of a marked overproduction of products of the cortisol C-18-oxidation pathway, 18-hydroxycortisol and 18-oxocortisol, which are more abundant than aldosterone and 18-hydroxycorticosterone. A family with 3 affected sibs has been studied by our group. In other clinical situations, classical zona fasciculata mineralocorticoids (deoxycorticosterone [DOC], corticosterone, and their 18-hydroxy compounds) are secreted in excess. The hypertensive diseases of this zone are rare DOC-secreting tumors and two forms of congenital adrenal hyperplasia, the 11β-hydroxylase and 17α-hydroxylase deficiency syndromes, which are identified by the presence of hypokalemia and suppressed renin activity. DOC is the only mineralocorticoid hormone (MCH) oversecreted in the 11-hydroxylase deficiency syndromes, while all ACTH-dependent MCH levels are very high in the 17-hydroxylase deficiency syndromes. The molecular basis of the gene abnormalities in these disorders is currently under investigation, and preliminary data obtained in some of our patients are presented. Finally, a syndrome of apparent mineralocorticoid (MC) excess, which is not a primary disorder of the adrenal cortex, shows the association of unexplained hypermineralocorticoid state with a decreased rate of peripheral 11β-hydroxyde-hydrogenation of cortisol (F) to cortisone (E). Studies on this syndrome have led to the hypothesis that peripheral F inactivation is the normal mechanism permitting specific MC recognition. The syndrome exists in two forms both characterized by a decreased turnover of a normal level of plasma F, but in the type 1 variant, an elevated F/E metabolite ratio is found, whereas in the type 2 variant, this ratio is normal. Three patients with the latter form have recently been described by us and are shortly illustrated. A possible role of this impaired F metabolism in the pathogenesis of other forms of hypertension, such as liquorice- and carbenoxolone-induced hypertension, has recently been suggested.
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