Beta-hydroxysteroid Dehydrogenase Deficiency Research Articles

A novel nonstop mutation in the stop codon and a novel missense mutation in the type II 3beta-hydroxysteroid dehydrogenase (3beta-HSD) gene causing, respectively, nonclassic and classic 3beta-HSD deficiency congenital adrenal hyperplasia.

We investigated two novel point mutations in the human type II 3beta-hydroxysteroid dehydrogenase (3beta-HSD) gene causing a mild and a severe form of 3beta-HSD deficiency congenital adrenal hyperplasia. The first is a nonstop mutation in the normal stop codon 373 of the gene in exon IV [TGA (Stop) --> TGC (Cys) = Stop373C) identified from one allele of a female child with premature pubarche whose second allele had an E142K mutation. The Stop373C mutation predictably results in an open reading frame and a mutant-type (MT) II 3beta-HSD protein containing 467 amino acid residues, compared with the 372 amino acid residues of wild-type (WT) protein. The second is a homozygous missense mutation in codon 222 [CCA (Pro) --> ACT (Thr) = P222T] in the gene identified from a female neonate with salt-wasting disorder. The pcDNA vectors containing the constructs of WT II 3beta-HSD cDNA, WT cDNA with the open reading frame (WT cDNA(+)), MT Stop373C with the open reading frame (Stop373C(+)) and MT P222T cDNA were transfected in COS-I and 293T cells and expressed a similar amount of 3beta-HSD mRNA. The enzyme activity in intact cells using pregnenolone and dehydroepiandrosterone as substrate in the medium (1 micromol/liter) was identical between the WT cDNA and the WT cDNA(+), but was decreased to 27% of the WT enzymes at 6 h by MT Stop373C(+) enzyme, and was undetectable by P222T enzyme. In the homogenates of the cells, both MT Stop373C(+) and P222T enzyme activities and enzymes were undetectable despite clear detection of WT enzyme activities and WT enzymes. LH response to an LHRH analog stimulation in the pubertal female with the Stop373C/E142K genotypes and in a pubertal female with compound 273/318 frameshift genotypes were comparable to and higher than control females, respectively. In conclusion, a structurally lengthy MT II 3beta-HSD enzyme due to a nonstop mutation was relatively detrimental in intact cells causing the nonclassic phenotype of 3beta-HSD deficiency. A missense P222T mutation was seriously detrimental, causing the classic phenotype of 3beta-HSD deficiency. The undetectable Stop373C and P222T enzymes on Western blottings, together with the respective in vivo and in vitro data, suggest that a relative instability of Stop373C enzyme and a profound instability of the P222T enzyme are likely the detrimental molecular mechanisms. The increased LH in the female with the frameshift genotype and the appropriate LH response in the female with the nonstop genotype correlated with predictably severe and mild ovarian type II 3beta-HSD deficiency, respectively.

Sonographic Appearance of Congenital Adrenal Hyperplasia In Utero

Congenital adrenal hyperplasia (CAH) is an autosomal recessive disorder with a deficiency of one of the enzymatic activities necessary for cortisol synthesis. More than 90% of cases of CAH are caused by 21-hydroxylase deficiency. Other enzymatic defects include 11β-hydroxylase and 3β-hydroxysteroid dehydrogenase deficiency. The clinical aspect depends on the severity of the enzymatic deficiency and its position within the chain of reactions that leads to the synthesis of the various hormones. Undiagnosed, the disease may cause life-threatening problems (electrolyte losses and dehydration) in infancy and also virilization and long-term physical and psychologic effects. 1-3 Current treatment of patients with CAH includes administration of glucocorticoids to suppress excessive adrenal androgen secretion. The objective is to achieve normal growth, pubertal development, sexual function, and fertility. The aim of this report is to describe the appearance of th ie adrenal glands during the third trimester in a fetus with known CAH. This may render the diagnosis easier in patients without known disease and may prompt adequate treatment.

SIGMOID RECONFIGURED VAGINAL CONSTRUCTION IN CHILDREN

We present a modified technique of sigmoid neovaginal construction in children that protects the sigmoid pedicle from traction, allows easy adjustment of caliber and reorients the mucosal fold in a longitudinal direction. From 1997 to 2000, 10 genetically male (46 XY) children 1 to 13 years old underwent construction of a neovagina with sigmoid, incorporating the Yang-Monti concept of intestinal reconfiguration. The diagnosis was androgen insensitivity in 7 patients, congenital adrenal hyperplasia in 2 due to 17 alpha-hydroxylase deficiency and 3 beta-hydroxysteroid dehydrogenase deficiency, respectively, and bladder exstrophy in 1 who required sex reassignment. Eight children had an adequate caliber neovagina after an initial period of systematic dilation. In 1 case a relevant stricture required reoperation using the same technique and the outcome was good. In another child a stricture developed in the middle of the reconfigured sigmoid segment and a regular dilation schedule is still being followed after 23 months of followup. The new sigmoid reconfiguration technique enables the use of smaller dimension intestinal segments and construction of a long vaginal conduit of adequate caliber. Its optimal adequacy for penetration must be assessed in the future after these patients begin sexual activity.

Androgens, Androgen Receptors, and Male Gender Role Behavior

Studies of genetic males with single gene mutations that impair testosterone formation or action and consequently prevent development of the normal male phenotype provide unique insight into the control of gender role behavior. 46,XY individuals with either of two autosomal recessive mutations [17β-hydroxysteroid dehydrogenase 3 (17β-HSD3) deficiency or steroid 5α-reductase 2 (5α-R2) deficiency] have a female phenotype at birth and are raised as females but frequently change gender role behavior to male after the expected time of puberty. In contrast, genetic males with mutations that impair profoundly the function of the androgen receptor are also raised as females and have consistent female behavior as adults. Furthermore, the rare men with mutations that impair estrogen synthesis or the estrogen receptor have male gender role behavior. These findings indicate that androgens are important determinants of gender role behavior (and probably of gender identity) and that this action is mediated by the androgen receptor and not the result of conversion of androgen to estrogen. The fact that all genetic males with 17β-HSD3 or 5α-R2 deficiency do not change gender role behavior indicates that other factors are also important determinants of this process.

Determination of 17alpha-hydroxypregnenolone in human plasma by routine isotope dilution mass spectrometry using benchtop gas chromatography-mass selective detection.

A first assay based on stable isotope dilution/gas chromatography-mass spectrometry has been developed for plasma 17alpha-hydroxypregnenolone, the leading marker of 3beta-hydroxysteroid dehydrogenase deficiency. Equilibration of plasma with internal standard was followed by solid phase extraction. After clean up using Sephadex LH-20 mini columns, heptafluorobutyrates were prepared as derivatives. Quantification was achieved by selected ion monitoring of m/z 467.0 (analyte) and m/z 471.0 (internal standard). 0.030 pmol of 17alpha-hydroxypregnenolone gave a signal to noise ratio of 3.7. Calibration plot was linear. Spiking experiments showed good accuracy with relative errors < 3.7%. Intraassay precision CV was 8.3% and interassay precision CV was 5.6%. Requiring small amounts of plasma, the rapid, convenient work up and the application of bench top GC/MS instrumentation proved our method suitable for routine clinical use in adults and children.

Plasma 17-OH pregnenolone: comparison of a time-resolved fluoroimmunoassay using a new tracer 17-OH pregnenolone-3-oxyacetyl-biotine with a radioimmunoassay using 125I 17-OH pregnenolone-3-hemisuccinate-histamine

In this article we described, for the first time to our knowledge, the development of a new non isotopic immunoassay (time resolved-fluoroimmunoassay) for determining 17α-hydroxypregnenolone levels in plasma or serum. This steroid is indeed the most relevant steroid for the diagnosis of 3β-hydroxysteroid dehydrogenase deficiency. For the hapten tracer, we synthesized a biotin-oxyacetyl 17-hydroxypregnenolone conjugate. A specific polyclonal rabbit anti-17-hydroxypregnenolone was indirectly bound via an immobilized sheep anti-rabbit antibody on microtiter plate wells. The amount of biotin-17-hydroxypregnenolone conjugate bound was then measured by adding Streptavidin-Europium, and the Europium fluorescence was quantified by Time Resolved –Fluorescence (TR-FIA, Delfia System). The plasma 17-hydroxypregnenolone levels of this non isotopic assay were comparatively measured with a radioimmunoassay previously published and using the same anti 17-hydroxypregnenolone antibody. In both cases, the assays were performed after a extraction step and a chromatographic step. The sensitivity of this 17-hydroxypregnenolone time resolved-fluoroimmunoassay was higher than that of 17-hydroxypregnenolone radioimmunoassay. The compared results of plasma 17-hydroxypregnenolone, performed with these two methods were not significantly different. A practical advantage is the stability of the biotine tracer, comparatively to the radioactive 125I 17-hydroxypregnenolone tracer which requires a new labeling every two months.

Recent advances in the molecular genetics of congenital and acquired primary adrenocortical failure.

IntroductionIn recent years there have been many advances in ourunderstanding of the molecular pathogenesis of both congenitaland acquired adrenocortical failure (autoimmune or otherwise).As well as providing some fascinating insights into adrenalgland development and steroid hormone biosynthesis, therecognition of these various distinct disorders, either at aclinical or molecular genetic level, often has implications forthe management of the patient and their immediate family. In thispaper, we review the salient clinical and molecular features of thevarious causes of primary adrenocortical failure (Table 1).Genetics of autoimmune Addison’s diseaseAutoimmune Addison’s disease (AAD) is a chronic disorder ofthe adrenal gland, characterized by insufficiency of adrenocor-tical hormones due to autoimmune destruction of steroidogenicadrenocortical cells (Oelkers, 1996). The cytochrome P450enzymes involved in steroidogenesis, including 21-hydroxylase(Baumann-Antczak et al., 1992; Winqvist et al., 1992), 17-hydroxylase (Krohn et al., 1992) and side chain cleavageenzyme (Winqvist et al., 1993) have been identified as primaryautoantigens in AAD. With the overall decrease in theprevalence of tuberculosis, AAD has emerged as the mostcommon cause of primary adrenal failure in developedcountries (Nerup, 1974; Kong & Jeffcoate, 1994). Nevertheless,AAD is a relatively rare endocrinopathy; recent epidemiologi-cal studies showing an estimated prevalence in the generalEuropean population of about 100 per million (Kong J Laureti et al., 1999).The results of human leucocyte antigen (HLA) typing, takentogether with the clinical heterogeneity of presentation anddifferent modes of inheritance, have suggested distinctpathogenic bases for different forms of AAD. Thus, AADmay occur in isolation, as a manifestation of the autoimmunepolyendocrinopathy type 1 syndrome (APS1), or as part of theautoimmune polyendocrinopathy type 2 (APS2) syndrome(Table 1) (Spinner et al., 1968; Neufeld et al., 1981; Maclaren& Riley, 1986).Autoimmune polyendocrinopathy type 1 syndrome: amonogenic autoimmune disorderIn the autoimmune polyendocrinopathy type 1 (APS1)syndrome, which is also known as the autoimmune poly-endocrinopathy, candidiasis and ectodermal dystrophy(APECED) syndrome, AAD occurs in association withautoimmune hypoparathyroidism, chronic mucocutaneous can-didiasis and other organ-specific autoimmune disorders. Theseinclude type 1 diabetes, primary gonadal failure, perniciousanaemia, chronic active hepatitis and hypothyroidism (Neufeldet al., 1981; Ahonen et al., 1990). The age of onset of AAD inAPS1 is typically between 11 and 15years, although othermanifestations of APS1 (e.g. hypoparathyroidism and candi-diasis) are likely to present at an earlier age. APS1 is amonogenic disorder with autosomal recessive inheritance,affecting both sexes with equal prevalence (Ahonen, 1985),and is rare in most populations. However, because of foundereffects, it is relatively common in the Finnish population andIranian Jews with estimated prevalences of 1/25000 and 1/9000, respectively (Ahonen, 1985; Zlotogora & Shapiro, 1992).Initial genetic studies of APS1 focused on HLA, and noassociation of this disorder with any specific HLA haplotypehas been found (Neufeld et al., 1981; Maclaren & Riley, 1986;Aaltonen et al., 1993; Huang et al., 1996). The gene underlyingAPS1 was subsequently localized on chromosome 21q22 bylinkage analysis (Aaltonen et al., 1994) and identified bypositional cloning (Finnish-German APECED consortium,1997; Nagamine et al., 1997). This gene, designated auto-immune regulator-1 (AIRE-1), encodes a 545 amino acidprotein that has two plant homeodomain (PHD)-type zinc-finger motifs, suggesting a role as a transcription factor(Finnish-German APECED consortium, 1997; Nagamine etal., 1997). AIRE-1 mRNA is expressed in lymphoid tissuesincluding thymus, lymph node and spleen, and possibly also inother tissues including the adrenal cortex (Finnish-GermanAPECED consortium, 1997; Nagamine et al., 1997), whichsuggests that it may have an important role in the developmentof a normal immune response.

Mutations in the Type II 3β-Hydroxysteroid Dehydrogenase (HSD3B2) Gene Can Cause Premature Pubarche in Girls

Congenital adrenal hyperplasia (CAH) caused by a deficiency of 3β-hydroxysteroid dehydrogenase (3β-HSD) is a rare autosomal recessive disorder affecting both boys and girls. The clinical presentation is heterogeneous. Girls with premature pubarche as well as hirsute women with increased ACTH-stimulated delta-5 steroid levels were previously thought to have nonclassic or mild CAH secondary to 3β-HSD deficiency. Most efforts have failed to reveal mutations in the type II 3β-HSD gene (HSD3B 2) in these patients, apparently ruling out a mutant 3β-HSD protein as the cause. This study screened HSD3B2 for mutations in nine girls with premature pubarche who had a hormonal diagnosis of 3β-HSD deficiency. All of them had a circulating level of 17-hydroxypregnenolone 6 or more standard deviations above the mean (range = 48–351 nmol/liter). ACTH-stimulated levels of dehydroepiandrosterone were elevated in four of the nine girls. A homozygous T259M mutation was found in one girl, and a new mixed heterozygous G129R/P222H mutation was found in two sisters. Individuals with mutations had the highest levels of stimulated 17-hydroxypregnenolone, but levels of stimulated dehydroepiandrosterone (DHEA) overlapped between the girls with or without mutations and normal control subjects. The investigators concluded that mutations in HSD3B2 may cause premature pubarche in girls with elevated levels of ACTH-stimulated 17-hydroxypregnenolone. The cutoff level in the present series was 147 nmol/liter. Genotyping patients with premature pubarche will help to make a correct endocrine diagnosis of 3β-HSD deficiency.

Evaluation of the tubular and interstitial functions of the testis in 46,XY patients with ambiguous genitalia.

Investigation of the origin of sexual ambiguity is complex. Although testicular function has traditionally been assessed only by examining the steroidogenic capacity of Leydig cells and spermatogenesis, it has recently been shown that the measurement of serum anti-Müllerian hormone (AMH) as a marker of Sertoli cell function may also help clinicians. The aim of this study was to evaluate both Leydig and Sertoli cell functions in 46,XY patients with intersex states in order to establish biochemical patterns that would help to reach an etiologic diagnosis. We measured serum androgens, AMH and gonadotropins in 24 patients with sexual ambiguity and XY karyotype: 8 with gonadal dysgenesis (GD), 3 with 3beta-hydroxysteroid dehydrogenase deficiency (3betaHSD), 5 with androgen insensitivity syndrome (AIS), 4 with 5alpha-reductase 2 (SRD5A2) deficiency, and 4 were of unknown origin or idiopathic. Our results showed that while testosterone was low and gonadotropins elevated in patients with either GD or 3betaHSD, AMH was low in the former and high in the latter. Serum AMH and gonadotropins were normal or high in patients with 3betaHSD or AIS, but these could be distinguished by testosterone levels. Serum testosterone and gonadotropins were normal or high in AIS and SRD5A2 deficiency patients; however, while AMH was elevated in AIS, it was not the case in SRD5A2 deficiency patients, indicating that testosterone is sufficient to inhibit AMH within the testis. In idiopathic cases gonadotropins and testosterone were normal, and AMH was normal or low. We conclude that the combined measurement of androgens, AMH and gonadotropins helps to establish the diagnosis in intersex patients.

A New Insight Into the Molecular Basis of 3β-Hydroxysteroid Dehydrogenase Deficiency

Classical 3β-hydroxysteroid dehydrogenase/5–4 isomerase (3β-HSD) deficiency is a rare form of congenital adrenal hyperplasia that impairs steroidogenesis in both the adrenals and gonads resulting from mutations in the HSD3B2 gene, causing varying degrees of salt-loss in both sexes and incomplete masculinization of the external genitalia in genetic males. To date a total of 34 mutations (including 5 frameshift, 4 nonsense, 1 in-frame deletion, 1 splicing and 23 missense mutations) have been identified in the HSD3B2 gene. Results from functional charaterization studies of the mutant proteins agrees with the prediction that no functional type II 3β-HSD isoenzyme is expressed in the adrenals and gonads of the patients with the severe salt-losing form, whereas the nonsalt-losing form causes an incomplete loss in enzymatic activity, thereby leaving sufficient enzymatic activity to prevent salt loss. Recent studies have highlighted the fact that various mutations appear to have a drastic effect upon the stability of the protein, therefore providing molecular evidence of a new mechanism involved in classical 3β-HSD deficiency. Finally, the functional characterization of the missense mutations known to be involved in this autosomal recessive disorder provides valuable information concerning the structure-function relationships of the 3β-HSD enzyme superfamily.

Mutations in the type II 3beta-hydroxysteroid dehydrogenase (HSD3B2) gene can cause premature pubarche in girls.

Most previous studies have failed to demonstrate any mutations in the type II 3beta hydroxysteroid dehydrogenase (HSD3B2) gene in patients satisfying the hormonal criteria of nonclassic 3beta-hydroxysteroid dehydrogenase deficiency, suggesting that a mutant 3beta-hydroxysteroid dehydrogenase protein is not the cause of this disorder. We screened the HSD3B2 gene for mutations in girls with premature pubarche and a hormonal diagnosis of 3beta-hydroxysteroid dehydrogenase deficiency. From 30 girls with premature pubarche, we selected 9 whose ACTH-stimulated 17-hydroxypregnenolone levels were elevated (> or =6 SD) and screened the HSD3B2 gene for mutations. All patients were submitted to a standard ACTH stimulation test. Serum steroids were measured and compared to the mean level of pubertal stage matched control subjects. The four exons and exon-intron boundaries of the HSD3B2 gene were amplified by polymerase chain reaction and screened for mutations by denaturing gradient gel electrophoresis. The fragments with abnormal migration on denaturing gradient gel electrophoresis were directly sequenced. A homozygous T259M mutation was identified in one girl and a new compound heterozygous G129R/P222H mutation was identified in two sisters. The highest ACTH-stimulated 17-hydroxypregnenolone levels, 147, 339 and 351 nmol/l, were found in those patients with mutations in the HSD3B2 gene. In the patients without mutations, ACTH-stimulated 17-hydroxypregnenolone ranged from 48 to 111 nmol/l. ACTH-stimulated dehydroepiandrosterone levels had an overlap among the girls with and without mutations and the normal controls. Premature pubarche can be caused by mutations in the type II 3beta hydroxysteroid dehydrogenase gene.

New insight into the molecular basis of 3beta-hydroxysteroid dehydrogenase deficiency: identification of eight mutations in the HSD3B2 gene eleven patients from seven new families and comparison of the functional properties of twenty-five mutant enzymes.

Classical 3beta-hydroxysteroid dehydrogenase/delta5-delta4 isomerase (3betaHSD) deficiency is a form of congenital adrenal hyperplasia that impairs steroidogenesis in both the adrenals and gonads resulting from mutations in the HSD3B2 gene and causing various degrees of salt-wasting in both sexes and incomplete masculinization of the external genitalia in genetic males. To identify the molecular lesion(s) in the HSD3B2 gene in the 11 patients from the seven new families suffering from classical 3betaHSD deficiency, the complete nucleotide sequence of the whole coding region and exon-intron splicing boundaries of this gene was determined by direct sequencing. Five of these families were referred to Morel's molecular diagnostics laboratory in France, whereas the two other families were investigated by Peter's group in Germany. Functional characterization studies were performed by Simard's group in Canada. Following transient expression in 293 cells of each of the mutant recombinant proteins generated by site-directed mutagenesis, the effect of the 25 mutations on enzyme activity was assessed by incubating intact cells in culture with 10 nM [14C]-DHEA as substrate. The stability of the mutant proteins has been investigated using a combination of Northern and Western blot analyses, as well as an in vitro transcription/translation assay using rabbit reticulocyte lysates. The present report describes the identification of 8 mutations, in seven new families with individuals suffering from classical 3betaHSD deficiency, thus increasing the number of known HSD3B2 mutations involved in this autosomal recessive disorder to 31 (1 splicing, 1 in-frame deletion, 3 nonsense, 4 frameshift and 22 missense mutations). In addition to the mutations reported here in these new families, we have also investigated for the first time the functional significance of previously reported missense mutations and or sequence variants namely, A82T, A167V, L173R, L205P, S213G and K216E, P222H, T259M, and T259R, which have not previously been functionally characterized. Furthermore, their effects have been compared with those of the 10 previously reported mutant enzymes to provide a more consistent and comprehensive study. The present results are in accordance with the prediction that no functional 3betaHSD type 2 isoenzyme is expressed in the adrenals and gonads of the patients suffering from a severe salt-wasting form of CAH due to classical 3betaHSD deficiency. Whereas the nonsalt-losing form also results from missense mutation(s) in the HSD3B2 gene, which cause an incomplete loss in enzyme activity, thus leaving sufficient enzymatic activity to prevent salt wasting. The functional data described in the present study concerning the sequence variants A167V, S213G, K216E and L236S, which were detected with premature pubarche or hyperandrogenic adolescent girls suspected to be affected from nonclassical 3betaHSD deficiency, coupled with the previous studies reporting that no mutations were found in both HSD3B1 and/or HSD3B2 genes in such patients strongly support the conclusion that this disorder does not result from a mutant 3betaHSD isoenzyme. The present study provides biochemical evidence supporting the involvement of a new molecular mechanism in classical 3betaHSD deficiency involving protein instability and further illustrates the complexity of the genotype-phenotype relationships of this disease, in addition to providing further valuable information concerning the structure-function relationships of the 3betaHSD superfamily.

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

Objective: We sought to determine the prevalence of 3β-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 μmol/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 3β-hydroxysteroid dehydrogenase deficiency (>5-fold of the control mean value). Conclusion: 3β-Hydroxysteroid dehydrogenase–deficient nonclassic adrenal hyperplasia is rare even among adult hyperandrogenic patients with adrenal androgen excess. (Am J Obstet Gynecol 1999;181:596-600.)

17Beta-hydroxysteroid dehydrogenase-3 deficiency: diagnosis, phenotypic variability, population genetics, and worldwide distribution of ancient and de novo mutations.

17Beta-hydroxysteroid dehydrogenase-3 (17betaHSD3) deficiency is an autosomal recessive form of male pseudohermaphroditism caused by mutations in the HSD17B3 gene. In a nationwide study on male pseudohermaphroditism among all pediatric endocrinologists and clinical geneticists in The Netherlands, 18 17betaHSD3-deficient index cases were identified, 12 of whom initially had received the tentative diagnosis androgen insensitivity syndrome (AIS). The phenotypes and genotypes of these patients were studied. Endocrine diagnostic methods were evaluated in comparison to mutation analysis of the HSD17B3 gene. RT-PCR studies were performed on testicular ribonucleic acid of patients homozygous for two different splice site mutations. The minimal incidence of 17betaHSD3 deficiency in The Netherlands and the corresponding carrier frequency were calculated. Haplotype analysis of the chromosomal region of the HSD17B3 gene in Europeans, North Americans, Latin Americans, Australians, and Arabs was used to establish whether recurrent identical mutations were ancient or had repeatedly occurred de novo. In genotypically identical cases, phenotypic variation for external sexual development was observed. Gonadotropin-stimulated serum testosterone/androstenedione ratios in 17betaHSD3-deficient patients were discriminative in all cases and did not overlap with ratios in normal controls or with ratios in AIS patients. In all investigated patients both HSD17B3 alleles were mutated. The intronic mutations 325 + 4;A-->T and 655-1;G-->A disrupted normal splicing, but a small amount of wild-type messenger ribonucleic acid was still made in patients homozygous for 655-1;G-->A. The minimal incidence of 17betaHSD3 deficiency in The Netherlands was shown to be 1: 147,000, with a heterozygote frequency of 1:135. At least 4 mutations, 325 + 4;A-->T, N74T, 655-1;G-->A, and R80Q, found worldwide, appeared to be ancient and originating from genetic founders. Their dispersion could be reconstructed through historical analysis. The HSD17B3 gene mutations 326-1;G-->C and P282L were de novo mutations. 17betaHSD3 deficiency can be reliably diagnosed by endocrine evaluation and mutation analysis. Phenotypic variation can occur between families with the same homozygous mutations. The incidence of 17betaHSD3 deficiency is 0.65 times the incidence of AIS, which is thought to be the most frequent known cause of male pseudohermaphroditism without dysgenic gonads. A global inventory of affected cases demonstrated the ancient origin of at least four mutations. The mutational history of this genetic locus offers views into human diversity and disease, provided by national and international collaboration.

Congenital adrenal hyperplasia in pregnancy

The congenital adrenal hyperplasias (CAH) are a group of inherited enzymatic defects of adrenal steroid biosynthesis. Deficiencies of each enzyme required in the steroid biosynthesis pathway are known, and these deficiencies are all inherited as autosomal recessive disorders. During pregnancy, maternal and fetal problems are confined to women who have 21-hydroxylase deficiency (P450c21 deficiency), 11-hydroxylase deficiency (P450c11 deficiency), and 3 beta-hydroxysteroid dehydrogenase deficiency (3 beta HSD deficiency), because other adrenal enzyme deficiencies are not compatible with fertility. The interposition of the placenta on the hypothalamic-pituitary-adrenal axis and other endocrine changes during pregnancy impact considerably on the clinical evaluation of the congenital adrenal hyperplasias. Successful management of CAH in pregnancy requires a firm knowledge of normal adrenal anatomic and endocrine changes that occur during gestation. Women with severe forms of CAH have decreased fertility rates because of oligo-ovulation, and successful conception requires a combination of good therapeutic compliance, careful endocrine monitoring, and often ovulation induction. From a fetal and neonatal standpoint, accurate prenatal diagnosis of 21-hydroxylase deficiency and 11-hydroxylase deficiency is now possible, which allows for prenatal treatment in an attempt to minimize clinical problems in the neonates. Prevention of masculinization of affected female fetuses by corticosteroid suppression has been attempted in both 21-hydroxylase deficiency and 11beta-hydroxylase deficiency CAH, with variable degrees of success. This review provides an overview of the congenital adrenal hyperplasias and their management during pregnancy.

Variants of the Type II 3β-Hydroxysteroid Dehydrogenase Gene in Children with Premature Pubic Hair and Hyperandrogenic Adolescents

To ascertain the potential role of heterozygosity for 3β-hydroxysteroid (3β-HSD) deficiency in children with premature pubic hair and adolescent girls with hyperandrogenism, we performed single-strand conformational polymorphism (SSCP) analysis of the 3β-hydroxysteroid dehydrogenase type 2 (3β-HSD2) gene in 34 hyperandrogenic patients. Three sequence variants, two missense mutations and a 3′-UTR sequence variant, were detected among seven patients and in none of 100 healthy control subjects. One of these seven patients carried Leu236→ Ser on one3β-HSD2allele and Glu318→ STOP on one 21-hydroxylase (CYP21) allele. ACTH stimulation tests were performed in 5/7 patients with sequence variants and were compatible with decreased 3β-hydroxysteroid dehydrogenase activity in three. Thus, 7 of 34 (20.6%) mildly hyperandrogenic patients carry heterozygous sequence variants of the 3β-HSD2 gene. Since obligate heterozygotic carriers for congenital adrenal hyperplasia are typically asymptomatic, other genetic or environmental influences may contribute to the expression of hyperandrogenic symptoms in our patients.

Two Novel Homozygous Mutations in the Type II 3β-Hydroxysteroid Dehydrogenase(3β-HSD) Gene Causing Non-Salt Wasting and Salt Wasting 3β-HSD Deficiency Congenital Adrenal Hyperplasia (CAH) and the Utility of Hormonal Profiles for Diagnosising Bonafide 3β-HSD Deficiency CAH• 505

Two Novel Homozygous Mutations in the Type II 3β-Hydroxysteroid Dehydrogenase(3β-HSD) Gene Causing Non-Salt Wasting and Salt Wasting 3β-HSD Deficiency Congenital Adrenal Hyperplasia (CAH) and the Utility of Hormonal Profiles for Diagnosising Bonafide 3β-HSD Deficiency CAH• 505

Urinary cortisol metabolites in the assessment of peripheral thyroid hormone action: overt and subclinical hypothyroidism.

Biological assessment of peripheral thyroid hormone action may be important in subclinical hypothyroidism, where decision-making is often difficult. The impairment of urinary cortisol metabolites in overt hypothyroidism reflects an acquired 11 beta hydroxysteroid dehydrogenase (11 beta OHSD) deficiency, and is assessed in terms of a reduction in the tetrahydrocortisone (THE)/tetrahydrocortisol (THF) ratio or THE/THE + alpha THF ratio; the alpha THF/THF ratio reflects 5 beta reductase activity. The aim of this study was to determine if urinary cortisol metabolite ratios are a good index of peripheral thyroid hormone action in subclinical hypothyroidism. the THE/THF, THE/THF + alpha THF and alpha THF/THF ratios were measured in 24 h urine samples from 3 groups of subjects: 1) 18 euthyroid subjects; 2) 25 patients with elevated serum TSH and low FT4 levels (overt hypothyroidism); and 3) 25 patients with increased serum TSH and normal FT4 levels (subclinical hypothyroidism. 7/25 overtly and 5/25 subclinically hypothyroid patients had a THE/THF + alpha THF ratio below the mean control value -2 SD, while respectively 20/25 and 11/25 patients had a THE/THF ratio below the mean control value -2 SD. The mean THE/THF + alpha THF, THE/THF and alpha THF/THF ratios were significantly different among the 3 groups (ANOVA) and were lower in the overtly hypothyroid group than in the other two groups (Fisher's test); daily urine sodium output was also significantly different between the three groups and lower in the overtly and subclinically hypothyroid groups than in the control group (Fisher's test). FT3 and FT4 both correlated with THE/THF + alpha THF in the overtly hypothyroid patients (r = 0.43; p < 0.05 and r = 0.40; p < 0.05, respectively). In the subclinically hypothyroid patients, TSH correlated with THE/THF + alpha THF (r = 0.44; p < 0.05) and THE/THF (r = 0.43; p < 0.05). FT3, FT4 and TSH levels correlated with THE/THF + alpha THF (p < 0.001), THE/THF (p < 0.001), alpha THF/THF (p < 0.001) and daily natriuresis (p < 0.05) in the whole population (patients + controls). In conclusion, urinary cortisol metabolites, although impaired in overt hypothyroidism, are not an accurate index of peripheral thyroid hormone deficiency in subclinical hypothyroidism. We also identified an increase in the alpha THF/THF ratio in overt hypothyroidism, which may be related to 5 beta reductase disturbances.

The Molecular and Clinical Spectrum of 3β-hydroxysteroid Dehydrogenase Deficiency Disorder

Severe 3β-hydroxysteroid dehydrogenase (3β-HSD) deficiency in the adrenals and gonads is a well known cause of salt-wasting and non-salt-wasting forms of congenital adrenal hyperplasia (CAH), male pseudohermaphroditism and mild androgen excess symptoms in children and older females. A mild spectrum of Δ5 steroid abnormality in young children with premature pubarche and older females with hirsutism and menstrual disorder was presumed to be due to a mild variant of 3β-HSD deficiency CAH. Recent studies of the type II 3β-HSD gene encoding adrenal and gonadal 3β-HSD have indicated that only the severe 3β-HSD deficiency CAH results from a deleterious mutation in the gene. This indicates that the mild Δ5 steroid abnormality is not due to a variant of 3β-HSD deficiency CAH. The hormonal criteria for bona fide mild variants of 3β-HSD deficiency and etiology of mild Δ5 steroid abnormality in the patients remain to be investigated.

Abnormalities of aldosterone synthesis and action in children.

Genetic defects in aldosterone biosynthesis and action affect blood pressure and electrolyte homeostasis. Aldosterone synthase deficiency, salt-wasting forms of congenital adrenal hyperplasia, and adrenal hypoplasia congenita all cause aldosterone deficiency, signs of which include hyponatremia, hyperkalemia, hypovolemia, elevated plasma renin activity, and sometimes shock and death. Conversely, the inappropriate regulation of aldosterone synthesis seen in glucocorticoid-suppressible hyperaldosteronism may cause hypokalemia, suppressed plasma renin activity, and hypertension. Similar problems occur when the normal ligand specificity of the aldosterone receptor is lost, as in the syndrome of apparent mineralocorticoid excess due to 11 beta-hydroxysteroid dehydrogenase deficiency. The effects of aldosterone are mediated largely through activation of the epithelial sodium channel, and inactivating or activating mutations of this channel leads to signs of mineralocorticoid deficiency or excess, termed pseudohypoaldosteronism and Liddle's syndrome, respectively.