The incidence of late-onset congenital adrenal hyperplasia due to 3 beta-hydroxysteroid dehydrogenase deficiency among hirsute women

Comprehensive genotyping of Turkish women with hirsutism

INTRODUCTION

Hirsutism is a medical sign rather than a disease affects 5-8% of women of reproductive age. Hirsutism is associated with hyperandrogenemia in most patients excluding those with idiopathic hirsutism (IH). The most common cause of hirsutism is polycystic ovary syndrome (PCOS) followed by IH and idiopathic hyperandrogenemia (IHA); however, the clinical presentation of non-classical congenital adrenal hyperplasia (NCAH) in females is often indistinguishable from other hyperandrogenic disorders with common clinical signs such as hirsutism.

OBJECTIVE

The primary aim of the study is to examine the physical properties of the three genes and to make a detailed comparison of the mutations with the clinical data to contribute the etiology of hirsutism.

SUBJECTS AND METHODS

122 women admitted to the Endocrinology Clinic at Erciyes University Hospital with hirsutism were enrolled in the study between 2013-2014. All the participants were clinically evaluated. Protein-encoding exons, exon-intron boundaries of CYP21A2 (including proximal promoter), CYP11B1 and HSD3B2 genes were analyzed via state-of-the-art genetic studies.

RESULTS

DNA sequencing analyses revealed two homozygous and three compound heterozygous 21-hydroxylase deficient (21OHD) NCAH patients. Additionally, three novel CYP21A2 mutations (A89V, M187I and G491S) and two novel CYP11B1 mutations (V188I and G87A) were determined. The frequencies of heterozygous mutations in CYP21A2 (including promoter), CYP11B1 and HSD3B2 genes were determined as 26.5% (15% coding region, 11.5% promoter), 11.5% and 0%, respectively.

CONCLUSION

21OHD-NCAH prevalence was determined to be ~4%. Unexpectedly, high heterozygous mutation rates were observed in CYP11B1 gene and CYP21A2 promoter region. CYP11B1 and HSD3B2 deficiencies were not prevalent in Turkish women with hirsutism despite the existence of higher heterozygous mutation rate in CYP11B1.

Prevalence of 3beta-hydroxysteroid dehydrogenase-deficient nonclassic adrenal hyperplasia in hyperandrogenic women with adrenal androgen excess

OBJECTIVE

We sought to determine the prevalence of 3beta-hydroxysteroid dehydrogenase-deficient nonclassic adrenal hyperplasia among adult hyperandrogenic women with dehydroepiandrosterone sulfate excess.

STUDY DESIGN

Thirty consecutive hyperandrogenic women with hirsutism, oligomenorrhea, or both and dehydroepiandrosterone sulfate levels of >8.5 micromol/L and 24 control subjects were studied. Basal sex hormone binding globulin, total and free testosterone, dehydroepiandrosterone sulfate, 17-hydroxyprogesterone, and basal and 60-minute corticotropin-stimulated 17-hydroxypregnenolone and dehydroepiandrosterone were measured, and the increment (change from basal to 60-minute value) was calculated.

RESULTS

Twenty-six (87%) and 25 (83%) of the 30 hyperandrogenic patients studied had 60-minute dehydroepiandrosterone and change in 0- to 60-minute dehydroepiandrosterone levels greater than the mean + 2 SD of control subjects, respectively. Six (20%) and 6 (20%) of the 30 hyperandrogenic patients had 60-minute 17-hydroxypregnenolone and 0- to 60-minute change in 17-hydroxypregnenolone levels greater than the mean + 2 SD of control subjects, respectively. However, none of the subjects had either 60-minute 17-hydroxypregnenolone levels or 60-minute dehydroepiandrosterone levels or both associated with the diagnosis of genetically proved 3beta-hydroxysteroid dehydrogenase deficiency (>5-fold of the control mean value).

CONCLUSION

3beta-Hydroxysteroid dehydrogenase-deficient nonclassic adrenal hyperplasia is rare even among adult hyperandrogenic patients with adrenal androgen excess.

Congenital adrenal hyperplasia: molecular genetics and alternative approaches to treatment

Several autosomal recessive disorders affecting the adrenal cortex and its development and leading to defective cortisol biosynthesis are known under the collective term "congenital adrenal hyperplasia" (CAH). Over the last two decades, the genes causing most of these disorders have been identified and molecular genetics may supplement their clinical and biochemical diagnosis. In addition, new treatments have emerged; although gene therapy has yet to be applied in humans, studies are ongoing in gene transfer in adrenocortical cell lines and animal models. In this review, after a brief introduction on the developmental biology and biochemistry of the adrenal cortex and its enzymes, we will list the new developments in the genetics and treatment of diseases causing CAH, starting with the most recent findings. This order happens to follow adrenal steroidogenesis from the mitochondrial entry of cholesterol to cortisol synthesis; it is unlike other presentations of CAH syndromes that start with the most frequently seen syndromes, because the latter were also the first to be investigated at the genetic level and have been extensively reviewed elsewhere. We will start with the latest syndrome to be molecularly investigated, congenital lipoid adrenal hyperplasia (CLAH), which is caused by mutations in the gene coding for the steroidogenic acute regulatory (StAR) protein. We will then present new developments in the genetics of 3-beta-hydroxysteroid dehydrogenase (3 beta HSD), 17 hydroxylase and 17,20-lyase (P450c17), 11 hydroxylase (P450c11 beta), and 21 hydroxylase (P450c21) deficiencies. Alternative treatment approaches and gene therapy experiments are reviewed collectively in the last section, because they are still in their infantile stages.

Adrenal steroidogenesis is related to insulin in hyperandrogenic women

OBJECTIVE

To evaluate ovarian and adrenal steroid secretion in women with severe hyperandrogenism.

DESIGN

A prospective study.

SETTING

The Gynecological Endocrine Research Unit of the University Central Hospital, Oulu, Finland.

PATIENTS

Thirteen obese, hirsute women with severe hyperandrogenism.

INTERVENTIONS

Adrenocorticotropin hormone stimulation and dexamethasone suppression tests and selective catheterizations of the left ovarian and adrenal veins were performed.

MAIN OUTCOME MEASURES

The concentrations of insulin, P, 17-hydroxyprogesterone (17-OHP), androstenedione (A), T, DHEA, DHEAS, and cortisol were measured.

RESULTS

The secretory gradients of T and its precursors, P, 17-OHP, A, and DHEA in the selective catheterizations showed the adrenal to be the main source of excessive steroid production in these patients. The concentrations of P (r = 0.82), 17-OHP (r = 0.89), A (r = 0.84), T (r = 0.86), and cortisol (r = 0.87) in the adrenal vein showed a strong correlation with insulin measured from the same samples.

CONCLUSIONS

Excessive androgens were secreted mainly by the adrenals in these obese hyperinsulinemic women. Correlation analyses suggested that insulin stimulates adrenal androgen and cortisol secretion, which may constitute an important component of the pathogenetic mechanisms of hyperandrogenism and the polycystic ovary syndrome.

Defects in steroidogenic enzymes. Discrepancies between clinical steroid research and molecular biology results

Molecular biology has clarified the understanding of steroidogenic enzyme genetics. Nevertheless, there are discrepancies between fundamental and clinical experience. (1) Why do patients with "pure" 17 alpha-hydroxylase or 17,20-desmolase deficiency exist, when one cytochrome regulates both steps? A case of interest is discussed, who had "pure" 17,20-desmolase deficiency until adolescence, but additional 17 alpha-hydroxylase deficiency thereafter. (2) In 11 beta-hydroxylase deficiency, it was puzzling to find 18-hydroxylated compounds, and, in isolated hypoaldosteronism, normal cortisol, since 11 beta- and 18-hydroxylation were thought to be regulated together. This has now been explained by differences in the fasciculata and glomerulosa. The occurrence of 11 beta-hydroxylase deficiency of 17-hydroxylated steroids only, however, remains enigmatic. (3) 3 beta-Hydroxysteroid dehydrogenase deficiency does not only seem to exist in classic (mutations of type II gene), but also in late-onset cases. In them, no molecular basis could be found. (4) Also, in cholesterol side-chain cleavage, there is an inequity: while evidently one cytochrome regulates 20- and 22-hydroxylation, pregnenolone is formed when 20 alpha OH-cholesterol, but not when cholesterol, is added to adrenal tissue of deficient patients. Other factors (promoters, fusion proteins, adrenodoxin, cAMP-dependent expression of genes, and/or proteases), or hormonal replacement in patients may be responsible for these discrepancies.

Genetic diseases of steroid metabolism

All major classes of biologically active steroid hormones (progestins, mineralocorticoids, glucocorticoids, and sex steroids) are synthesized from cholesterol through 11 different bioconversions. With the exception of 5 alpha-reductase, all the enzymes mediating these reactions fall into two classes, cytochromes P450 and short-chain dehydrogenases. Cytochromes P450 are heme-containing membrane-bound proteins with molecular weights of approximately 50,000 that utilize molecular oxygen and electrons from NADPH-dependent accessory proteins to hydroxylate substrates. Short-chain dehydrogenases have molecular weights of 30,000-40,000, have tyrosine and lysine residues at the active site, and remove a hydride from the substrate, transferring the electrons of the hydride to NAD+ or NADP+. In most cases, this reaction is reversible so that the dehydrogenase can also function as a reductase under appropriate conditions. Inherited disorders in enzymes required for steroid biosynthesis have varying effects. Defects that prevent cortisol from being synthesized are referred to collectively as congenital adrenal hyperplasia. Because the enzymes required for cortisol biosynthesis in the adrenal cortex are in many cases required for the synthesis of mineralocorticoids and/or sex steroids, these classes of steroids may also not be synthesized normally. Thus, cholesterol desmolase and 3 beta-hydroxysteroid dehydrogenase deficiencies affect synthesis of all classes of steroids in both the adrenals and gonads. Steroid 21-hydroxylase deficiency, the most common cause (> 90% of cases) of congenital adrenal hyperplasia, can affect both mineralocorticoid and glucocorticoid synthesis, but androgen secretion is usually abnormally high due to shunting of accumulated precursors into this pathway. Excessive secretion of androgens and mineralocorticoids occurs in 11 beta-hydroxylase deficiency (the second most frequent form of congenital adrenal hyperplasia). Mineralocorticoid excess is also seen in 17 alpha-hydroxylase deficiency, but in this disorder sex steroid synthesis is defective. All defects that affect estrogen synthesis (deficiencies of cholesterol desmolase, 3 beta-hydroxysteroid dehydrogenase, 17 alpha-hydroxylase, aromatase, and 17 beta-hydroxysteroid dehydrogenase) are very rare, suggesting that the inability to synthesize placental estrogens may adversely affect fetal survival. A number of enzymes are expressed at sites of steroid action and regulate the amount of active steroid available to steroid receptors. Steroid 5 alpha-reductase converts testosterone to the more active dihydrotestosterone. Deficiency of this activity leads to incomplete development of male genitalia; 17 beta-hydroxysteroid dehydrogenase deficiency has similar phenotypic effects.(ABSTRACT TRUNCATED AT 400 WORDS)

3 beta-hydroxysteroid dehydrogenase deficiency in hyperandrogenism

OBJECTIVE

Deficient adrenocortical 3 beta-hydroxysteroid dehydrogenase activity has been reported in 5% to 30% of hyperandrogenic women. Our objective was to determine the incidence and degree of 3 beta-hydroxysteroid dehydrogenase deficiencies in hyperandrogenism.

STUDY DESIGN

A prospective study of adrenal function in patients with hyperandrogenism was performed in a tertiary care university medical center. Eighty-six consecutive patients with hirsutism or hyperandrogenic oligomenorrhea were studied; 26 healthy eumenorrheic women served as controls. All subjects underwent serum sampling at rest and a 1-hour adrenal stimulation test with 1 mg of intravenously corticotropin-(1-24). Dehydroepiandrosterone sulfate, androstenedione, sex hormone-binding globulin, total and free testosterone, and luteinizing and follicle-stimulating hormones were measured in basal serum; dehydroepiandrosterone, 17-hydroxyprogesterone, and 17-hydroxypregnenolone were measured in basal and corticotropin-stimulated serum. On the basis of experience with genetically defined 21-hydroxylase late-onset adrenal hyperplasia, patients were presumed to suffer from 3 beta-hydroxysteroid-deficient late-onset adrenal hyperplasia if they demonstrated a dehydroepiandrosterone or 17-hydroxypregnenolone response to corticotropin-(1-24) stimulation (absolute poststimulation level or net increment) greater than threefold the upper 95th percentile of controls.

RESULTS

Three women of two families (2.3%) had a 17-hydroxyprogesterone response consistent with 21-hydroxylase-deficient late-onset adrenal hyperplasia and were excluded from further study. Eighteen (21%) of the remaining patients had a 17-hydroxypregnenolone poststimulation increment above the upper 95th percentile of controls (13.9 nmol/L), and two had an elevated dehydroepiandrosterone increment (> 19.5 nmol/L). However, no patient exceeded threefold the upper control limit for either steroid response. Patients with an exaggerated dehydroepiandrosterone or 17-hydroxypregnenolone increment had higher circulating dehydroepiandrosterone sulfate levels but similar basal total and free testosterone, sex hormone-binding globulin, luteinizing and follicle-stimulating hormone concentrations, basal or stimulated androstenedione, dehydroepiandrosterone/androstenedione, and 17-hydroxypregnenolone/17-hydroxyprogesterone than their less responsive counterparts.

CONCLUSIONS

Although an exaggerated response of 17-hydroxypregnenolone to adrenal stimulation is common in hyperandrogenism, a response severe enough to merit consideration as 3 beta-hydroxysteroid dehydrogenase-deficient late-onset adrenal hyperplasia was not encountered in this unselected patient population, suggestive of the rarity of this disorder.