Improved test to identify heterozygotes for congenital adrenal hyperplasia without index case examination

Clinical and hormonal characteristics in heterozygote carriers of congenital adrenal hyperplasia

Non-classical congenital adrenal hyperplasia (NC-CAH) includes a group of genetic disorders due to a broad class of CYP21A2 variants identifying a disease-causing 'C' genotype. The heterozygous carriers of CYP21 mutations are at increased risk of developing clinically evident hyperandrogenism, even though clinical and laboratory characteristics are still underestimated. With the aim of obtaining a more accurate delineation of the phenotype of heterozygous carrier of CAH, we analyzed clinical, biochemical and molecular characteristics in a cohort of Sicilian subjects. Fifty-seven females with biallelic and monoallelic CYP21A2 variants classifying NC-CAH (24) and heterozygous carriers of CAH (33), respectively were selected. Forty-four females age-matched healthy controls were also enrolled and genotyped for CYP21A2. Clinical, hormonal and genetic data were collected. CYP21A2 monoallelic mutations, defining the heterozygous carriers state, were identified in subjects with clinical features including hirsutism, oligomenorrhoea, overweight and a PCO-like phenotype, particularly occurring in the age of adolescence. Consistently, levels of 17OHP and cortisol were found to be significantly different from NC-CAH. Overall, some clinical and laboratory findings including oligomenorrhea and 17OHP/cortisol ratio were observed as independent markers associated with carriers of CAH. Here we report a high prevalence of late-onset signs of polycystic ovary syndrome (PCOS) and hyperandrogenism in heterozygous carriers. The 17OHP/cortisol ratio may be a predictive tool to identify the carriers of CAH, even though specific cut-off values have not yet been identified.

Congenital Adrenal Hyperplasia Due to Steroid 21-Hydroxylase Deficiency: An Endocrine Society Clinical Practice Guideline

Objective

To update the congenital adrenal hyperplasia due to steroid 21-hydroxylase deficiency clinical practice guideline published by the Endocrine Society in 2010.

Conclusions

The writing committee presents updated best practice guidelines for the clinical management of congenital adrenal hyperplasia based on published evidence and expert opinion with added considerations for patient safety, quality of life, cost, and utilization.

Variations in the 3'UTR of the CYP21A2 Gene in Heterozygous Females with Hyperandrogenaemia

Heterozygosity for CYP21A2 mutations in females is possibly related to increased risk of developing clinical hyperandrogenism. The present study was designed to seek evidence on the phenotype-genotype correlation in female children, adolescents, and women with CYP21A2 mutations and variants in the 3'UTR region of the gene. Sixty-six patients out of the 169 were identified as carriers of CYP21A2 mutations. Higher values of stimulated 17 hydroxyprogesterone (17-OHP) levels were found in the carriers of the p.Val281Leu mutation compared to the carriers of other mutations (mean: 24.7 nmol/l versus 15.6 nmol/l). The haplotype of the ∗52C>T, ∗440C>T, and ∗443T>C in the 3'UTR was identical in all heterozygous patients with p.Val281Leu and the haplotype of the ∗12C>T and ∗52C>T was identical in all heterozygous patients with the p.Gln318∗. In conclusion, hyperandrogenaemic females are likely to bear heterozygous CYP21A2 mutations. Carriers of the mild p.Val281Leu mutation are at higher risk of developing hyperandrogenism than the carriers of more severe mutations. The identification of variants in the 3'UTR of CYP21A2 in combination with the heterozygous mutation may be associated with the mild form of nonclassic congenital adrenal hyperplasia and reveal the importance of analyzing the CYP21A2 untranslated regions for the appropriate management of this category of patients.

LC-MS/MS based determination of basal- and ACTH-stimulated plasma concentrations of 11 steroid hormones: implications for detecting heterozygote CYP21A2 mutation carriers

OBJECTIVE

Heterozygosity in 21-hydroxylase deficiency (21OHD) has been associated with hyperandrogenemic symptoms in children and adults. Moreover, the carrier status is mandatory for genetic counseling. We aimed at defining a hormonal parameter for carrier detection by mass spectrometry.

DESIGN

Eleven basal and ACTH-stimulated steroid hormones of heterozygous carriers of CYP21A2 mutations and control individuals were compared.

METHOD

Hormones were determined in plasma samples by liquid chromatography tandem mass spectrometry (LC-MS/MS) in 58 carriers (35 males, 23 females, age range 6-78 years) and 44 random controls (25 males, 19 females, age range 8-58 years).

RESULTS

Heterozygotes could be identified best applying the 17-hydroxyprogesterone+21-deoxycortisol/cortisol×1000 ((17OHP+21S)/F×1000) equation 30  min after ACTH injection. An optimal cut-off value of 8.4 provided 89% sensitivity and specificity. Considering this data and a published frequency of heterozygotes of 1/50 to 1/61, the positive predictive value (PPV) of this cut-off is 12%. Of note, the negative predictive value (NPV) excluding heterozygosity in a given patient is 99.8%.

CONCLUSION

Considering only marginal biochemical effects anticipated from heterozygosity, the stimulated ((17OHP+21S)/F×1000) identifies and excludes heterozygotes remarkably well. Nevertheless, LC-MS/MS cannot replace genetic testing, since sensitivity and specificity did not reach 100%. However, due to the considerably high NPV of the optimal cut-off and to a specificity of even 100% applying a cut-off higher than 14.7, hormonal assessment of heterozygosity can be of significant aid in conditions with limited access to genetic testing, as in some health care systems. The ((17OHP+21S)/F×1000) equation can guide diagnostic considerations in the differential diagnosis of hyperandrogenism.

Phenotypic variability of hyperandrogenemia in females heterozygous for CYP21A2 mutations

OBJECTIVES

The objective was to seek evidence on the prevalence and consequences of heterozygous CYP21A2 mutations in girls, adolescent, and adult females with clinical manifestation of androgen excess.

PATIENTS AND METHODS

The study included 64 girls diagnosed with premature adrenarche (PA) in childhood and 141 females with clinical hyperandrogenemia manifested in adolescence or adulthood. Direct DNA sequencing and multiplex ligation-dependent probe amplification analysis were used to identify mutations in the CYP21A2 gene.

RESULTS

(1) Thirty-four patients were diagnosed with nonclassical-congenital adrenal hyperplasia (NC-CAH) based on the 17-hydroxyprogesterone (17-OHP) levels and the presence of two mutations in CYP21A2 and therefore were excluded from the study, 66 were found to be heterozygotes and finally 105 had no identifiable mutations. The most frequent mutations among the carriers were the mild p.Val281 Leu and p.Qln318stop. Higher levels of mean stimulated 17-OHP were found in the carriers of the p.Val281 Leu. (2) A notable increased allelic frequency for the known p.Asn493 Ser polymorphism was observed in the pool of females with hyperandrogenemia in whom no mutation was identified. (3) In girls, who presented early with PA, 26.6% were diagnosed with NC-CAH and carried two mutations, 28.7% were identified as heterozygotes 43.7% had no identifiable genetic defect in the translated region of the CYP21A2 gene. On the contrary, in the group of 141 females with late onset hyperandrogenemia, the presence of 2 mutations was detected in 12%, 1 mutation in 33.4% and no mutation in 54.6%.

CONCLUSIONS

The carrier status for 21-OHD, may be an important factor in the variable phenotype of hyperandrogenism and may be a contributing factor for the early manifestation of the disease.

Precursor-to-product ratios reflect biochemical phenotype in congenital adrenal hyperplasia

Precursor-to-product ratios in steroid hormone metabolism may accurately reflect enzymatic activity and production of metabolites relative to their disappearance. The purpose of this study was to explore the use of direct precursor-to-product steroid ratios to discriminate between infants with congenital adrenal hyperplasia (CAH) due to 21- α -hydroxylase deficiency and infants with no disorder, thus characterizing the biochemical phenotype in CAH. Deidentified dried blood spot samples from confirmed CAH cases identified by newborn screen (CAH-positive, N = 8) and from cases with no disorder (CAH-negative, N = 10) were obtained from the California State Newborn Screening Program. Samples (∼6.25 mm circular spots) underwent methanol and water extraction (9:1 ratio). Deuterated steroids served as isotope internal standards. 17-α-hydroxyprogesterone (17-OHP), 11-deoxycortisol (S), androstenedione (A4) and cortisol (F) concentrations were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and the 17-OHP/S, 17-OHP/A4, and S/F ratios were calculated. The mean 17-OHP and A4 concentrations in samples from CAH cases were significantly increased when compared to cases with no disorder (p = 0.003 for both). 17-OHP/S and 17-OHP/A4 ratios were also significantly elevated in CAH cases (p = 0.007 and p < 0.001, respectively). In contrast, S and F concentrations and the S/F ratio were similar between the two groups. In CAH, the elevated 17-OHP/S ratio is a biomarker of diminished 21-α-hydroxylase activity, and the elevated 17-OHP/A4 ratio is a biomarker of adrenal androgen excess via increased 17,20-lyase activity. The similar S/F ratio indicates that the rate of production via 11-β-hydroxylase and disappearance of F is maintained in CAH.

Zona fasciculata 21-hydroxysteroids and precursor-to-product ratios in 21-hydroxylase deficiency: further characterization of classic and non-classic patients and heterozygote carriers

INTRODUCTION

Although much is known about the increased levels of the 21-hydroxylase substrates 17-hydroxyprogesterone (17OHP) and 21-deoxycortisol (21DF) - the biochemical markers of all forms of 21-hydroxylase deficiency (21OHD), only limited information is available on the zona fasciculata (ZF) products distal to the enzymatic block: 11-deoxycortisol (S), 11-deoxycorticosterone (DOC), and corticosterone (B).

OBJECTIVE

To investigate whether basal and post-ACTH levels of S, DOC, and B and the 21-hydroxylase precursor-to-product ratios determined by tandem mass spectrometry preceded by high-performance liquid chromatography separation (liquid chromatography-tandem mass spectrometry) could disclose distinct profiles in genotypically confirmed classic (no.=14) and non-classic (NC) (no.=18) patients, heterozygote carriers (no.=61) and wildtypes (WT) (no.=27) for 21OHD.

RESULTS

Salt wasting (SW) and simple virilizing (SV) had higher basal levels of DOC with no further increase in response to ACTH. Stimulated DOC was similar in 21OHD patients and carriers but was reduced as compared to WT. ACTH-stimulated B increased gradually from SW and SV through WT. The post-ACTH 21DF/B ratio was able to detect 92% of the carriers among WT. All NC patients could be detected by post-ACTH 17OHP/DOC and 21DF/B, with no overlap with 21OHD carriers.

CONCLUSION

Although 21-hydroxylase is a key enzymatic step in both 17-hydroxy and 17-deoxy pathways of ZF, the reaction is mostly affected in the latter pathway, leading to a significant impairment of B production, which may further characterize the 21OHD subtypes. Also, the precursor-to-product ratios, particularly 21DF/B, can demonstrate the distinctive outline of 21OHD subtypes, including carriers and normal subjects.

Superior discriminating value of ACTH-stimulated serum 21-deoxycortisol in identifying heterozygote carriers for 21-hydroxylase deficiency

BACKGROUND

Congenital adrenal hyperplasia caused by classic 21-hydroxylase deficiency (21OHD) is an autosomal recessive disorder with a high prevalence of asymptomatic heterozygote carriers (HTZ) in the general population, making case detection desirable by routine methodology. HTZ for classic and nonclassic (NC) forms have basal and ACTH-stimulated values of 17-hydroxyprogesterone (17OHP) that fail to discriminate them from the general population. 21-Deoxycortisol (21DF), an 11-hydroxylated derivative of 17OHP, is an alternative approach to identify 21OHD HTZ.

OBJECTIVE

To determine the discriminating value of basal and ACTH-stimulated serum levels of 21DF in comparison with 17OHP in a population of HTZ for 21OHD (n = 60), as well as in NC patients (n = 16) and in genotypically normal control subjects (CS, n = 30), using fourth generation tandem mass spectrometry after HPLC separation (LC-MS/MS).

RESULTS

Basal 21DF levels were not different between HTZ and CS, but stimulated values were increased in the former and virtually nonresponsive in CS. Only 17·7% of the ACTH-stimulated 21DF levels overlapped with CS, when compared to 46·8% for 17OHP. For 100% specificity, the sensitivities achieved for ACTH-stimulated 21DF, 17OHP and the quotient [(21DF + 17OHP)/F] were 82·3%, 53·2% and 87%, using cut-offs of 40, 300 ng/dl and 46 (unitless), respectively. Similar to 17OHP, ACTH-stimulated 21DF levels did not overlap between HTZ and NC patients. A positive and highly significant correlation (r = 0·846; P < 0·001) was observed between 21DF and 17OHP pairs of values from NC and HTZ.

CONCLUSION

This study confirms the superiority of ACTH-stimulated 21DF, when compared to 17OHP, both measured by LC-MS/MS, in identifying carriers for 21OHD. Serum 21DF is a useful tool in genetic counselling to screen carriers among relatives in families with affected subjects, giving support to molecular results.

Congenital adrenal hyperplasia due to steroid 21-hydroxylase deficiency: an Endocrine Society clinical practice guideline

OBJECTIVE

We developed clinical practice guidelines for congenital adrenal hyperplasia (CAH).

PARTICIPANTS

The Task Force included a chair, selected by The Endocrine Society Clinical Guidelines Subcommittee (CGS), ten additional clinicians experienced in treating CAH, a methodologist, and a medical writer. Additional experts were also consulted. The authors received no corporate funding or remuneration.

CONSENSUS PROCESS

Consensus was guided by systematic reviews of evidence and discussions. The guidelines were reviewed and approved sequentially by The Endocrine Society's CGS and Clinical Affairs Core Committee, members responding to a web posting, and The Endocrine Society Council. At each stage, the Task Force incorporated changes in response to written comments.

CONCLUSIONS

We recommend universal newborn screening for severe steroid 21-hydroxylase deficiency followed by confirmatory tests. We recommend that prenatal treatment of CAH continue to be regarded as experimental. The diagnosis rests on clinical and hormonal data; genotyping is reserved for equivocal cases and genetic counseling. Glucocorticoid dosage should be minimized to avoid iatrogenic Cushing's syndrome. Mineralocorticoids and, in infants, supplemental sodium are recommended in classic CAH patients. We recommend against the routine use of experimental therapies to promote growth and delay puberty; we suggest patients avoid adrenalectomy. Surgical guidelines emphasize early single-stage genital repair for severely virilized girls, performed by experienced surgeons. Clinicians should consider patients' quality of life, consulting mental health professionals as appropriate. At the transition to adulthood, we recommend monitoring for potential complications of CAH. Finally, we recommend judicious use of medication during pregnancy and in symptomatic patients with nonclassic CAH.

An update to 21-hydroxylase deficient congenital adrenal hyperplasia

Congenital adrenal hyperplasia (CAH) due to deficiency of the enzyme 21-hydroxylase (21-OH) is distinguished in classical (C-CAH) and non-classical form (NC-CAH), and it is also one of the most common autosomal recessive inherited disorders in humans. The prevalence of C-CAH is between 1:10,000 and 1:15,000 among the live neonates of North America and Europe while the NC-CAH occurs in approximately 0.2% of the general white population. The highest incidence of CAH (1:282 and 1:2141, respectively) has been evaluated in Yupik Eskimos in Alaska and in the populations of the island La Reunion (France), while the lower was detected in New Zealand newborns (0.3%). Nowadays, it has been established that except for the adrenal cortex in CAH cases, the adrenal medulla was also affected. In human 21-OH deficient adrenal gland it has been discovered that not only the chromaffin cells formed extensive neurites, expanding between adrenocortical cells, but also that the adrenal androgens promote outgrowth, whereas glucocorticoids preserve neuroendocrine cells. It seems that normal cortisol secretion by the adrenal cortex is necessary for adrenomedullary organogenesis. The synthesis of 21-OH is controlled by the active CYP21A2 gene located at a distance of 30 kb from a highly homologous pseudogene designated CYP21A1P.

Simultaneous quantitation of seven endogenous C-21 adrenal steroids by liquid chromatography tandem mass spectrometry in human serum

Quantitation of endogenous steroids is important in the diagnosis of several endocrine disorders. In this study we present a new method for simultaneous quantitation of cortisol, cortisone, 11-desoxycortisol, 21-desoxycortisol, corticosterone, 17-hydroxyprogesterone and 11-desoxycorticosterone in human serum by on-line extraction and LC-MS/MS. Analytes extraction was performed on-line using a 2-position and 6-port valve equipped with a monolithic silica cartridge. After chromatographic separation of all analytes, detection was performed in the multiple reaction monitoring mode using positive atmospheric pressure chemical ionization mode. Total imprecision of the assay ranged from 5.5 to 15.5%. Comparison with immunoassays yielded coefficients of 0.893 for cortisol, 0.848 for 11-desoxycortisol and 0.924 for 17-hydroxyprogesterone. The sensitivity of this method provides meaningful data for patients within normal and elevated range and it may be useful for the diagnosis of a variety of adrenal dysfunctions.

Diagnosis and management of congenital adrenal hyperplasia

Congenital adrenal hyperplasia is the name applied to a class of autosomal recessive disorders resulting from deficiency of one of five enzymes necessary for cortisol synthesis by the adrenal cortex. Congenital adrenal hyperplasia is most often attributable to steroid 21-hydroxylase deficiency, accounting for more than 90% of cases. This discussion will be limited to the most common form of the disease, highlighting methods of diagnostic screening and challenges in disease management.

Congenital adrenal hyperplasia

Congenital adrenal hyperplasia (CAH) due to deficiency of 21-hydroxylase is a disorder of the adrenal cortex characterised by cortisol deficiency, with or without aldosterone deficiency, and androgen excess. Patients with the most severe form also have abnormalities of the adrenal medulla and epinephrine deficiency. The severe classic form occurs in one in 15,000 births worldwide, and the mild non-classic form is a common cause of hyperandrogenism. Neonatal screening for CAH and gene-specific prenatal diagnosis are now possible. Standard hormone replacement fails to achieve normal growth and development for many children with CAH, and adults can experience iatrogenic Cushing's syndrome, hyperandrogenism, infertility, or the development of the metabolic syndrome. This Seminar reviews the epidemiology, genetics, pathophysiology, diagnosis, and management of CAH, and provides an overview of clinical challenges and future therapies.

A higher rate of hyperandrogenic disorders in female-to-male transsexuals

In an effort to elucidate the aetiology of female-to-male transsexualism (FM-TS) 12 out of an annual sample of 16 untreated female-to-male transsexuals (FMT), aged 19 years 7 months (19;7) to 44 years 8 months (44;8) [median age (M) 27;5] were assessed by means of sexual-medical questionnaires, physical and endocrinological examination. The control group consisted of 15 healthy women (CF), aged 19 years 2 months (19;2) to 36 years 1 month (36;1) (M 22;7) without gender identity disorder, who were not under hormonal medication (including contraceptives). Baseline levels of testosterone (T; ng/dl), androstenedione (A4; ng/dl), dehydroepiandrosterone sulfate (DHEAS; ng/ml), luteinizing hormone (LH; IU/l), follicle stimulating hormone (FSH; IU/l), and sex-hormone binding globuline (SHBG; microgram/dl) were measured. A standard single-dose ACTH stimulation test (250 micrograms ACTH IV; Synacthen) was performed with all subjects. Aldosterone (ALDO), corticosterone (B), deoxycorticosterone (DOC), progesterone (PROG), 17-hydroxyprogesterone (17OHP), 11-deoxycortisol (S), cortisol (F), cortisone (E), pregnenolone (PREG) and 17-hydroxypregnenolone (OHPREG) were assessed before and 60 min after ACTH stimulation. Transvaginal ultrasound was performed in nine out of 12 FMT (20;11 to 44;8, M 27;5; m 29.1 +/- 7.5) but not in CF. Results showed that 10 FMT (83.3%) and five CF (33.3%) were above normal values for at least one of the measured androgens. Baseline levels of T and A4 were significantly higher in FMT than in CF (T: 54.0 +/- 13.8 vs. 41.1 +/- 12.8; A4: 244.8 +/- 73.0 vs. 190.5 +/- 49.3; p < .05), whereas DHEAS, SHBG, LH and FSH did not differ between the groups. Unbound T (T/SHBG ratio) was higher in FMT (72.0 +/- 67.6) than in CF (26.4 +/- 15.1). Baseline levels of 17OHP, OHPREG and DOC were higher in FMT than in CF (p < .05). After ACTH stimulation 17OHP and OHPREG remained higher in FMT than in CF (p < .05). Single case analysis of ACTH stimulation test together with physical examination revealed symptoms for non-classical congenital adrenal hyperplasia (NC-CAH) in six FMT (50%) and two CF (13.3%). Eight out of nine FMT who were assessed by means of transvaginal ultrasound (i.e. 88.9%; 50.0% of 16) had polycystic ovaries (PCO). Oligomenorrhoea or menstrual dysregularities (81.7% of 16 FMT vs. 0% of CF), hirsutism (56.2% of 16 FMT vs. 13.3% of 15 CF) and adiposity (25.0% vs. 0%) were frequent in FMT, but not in CF. Hyperandrogenism with polycystic ovarian syndrome (PCOS) and adrenocortical hyperresponsiveness to ACTH seems to be a common finding in FMT. This offers support for a hormonal factor in the genesis of FM-TS. Because the prevalence of PCOS and NC-CAH in the female population is higher than FM-TS, the true nature of this factor and its interaction with environmental influences remains unknown.

Carriers of 21-hydroxylase deficiency are not at increased risk for hyperandrogenism

A deficiency of 21-hydroxylase activity is one of the most commonly inherited genetic disorders in man, with heterozygosity for CYP21 mutations affecting approximately 1 in 60 of the non-Jewish Caucasian population. We have hypothesized that heterozygosity for CYP21 mutations in women increases their risk of developing clinically evident hyperandrogenism, and that this risk is related to the severity of the mutation of CYP21 and/or the 17-hydroxyprogesterone (17-OHP) response to ACTH stimulation. To test these hypotheses, we studied 38 obligate carriers for 21-hydroxylase deficiency (i.e. mothers of children with congenital adrenal hyperplasia or nonclassic congenital adreanl hyperplasia), comparing them to 27 weight-, parity-, and age-matched controls. Premenopausal carriers, not receiving hormonal treatment (n = 27), had higher mean total and free testosterone [T; 2.02 +/- 0.55 vs. 1.56 +/- 0.65 nmol/L (P < 0.007) and 0.018 +/- 0.007 vs. 0.012 +/- 0.006 nmol/L (P < 0.007), respectively] and lower mean sex hormone-binding globulin (214 +/- 62 vs. 277 +/- 129 nmol/L; P < 0.03) levels compared to controls. There was no difference in the mean basal levels of dehydroepiandrosterone sulfate, androstenedione (A4), or 17-OHP between carriers and controls. As expected, carriers exhibited higher stimulated and net increment 17-OHP levels than controls [21.1 +/- 27.1 vs. 6.2 +/- 3.1 nmol/L (P < 0.01) and 19.0 +/- 26.5 vs. 4.4 +/- 2.8 nmol/L (P < 0.009), respectively]. However, no difference was observed in the response of A4 to ACTH-(1-24) stimulation. Of the 27 carriers studied biochemically, 2 (7.4%) had a stimulated 17-OHP value between 30.3-60.6 nmol/L, and 1 (3.7%) had a 17-OHP level above 60.6 nmol/L, suggestive of nonclassic adrenal hyperplasia. Of all carriers studied genetically (n = 36), 50.0% (18 of 36) had 1, 33% (12 of 36) had 2, and 16.7% (6 of 36) had 3 or more mutations. In 27.8% (10 of 36) of carriers, the mutations were contiguous, consistent with a large gene conversion. All 38 carriers were examined for historical and physical features of hyperandrogenism. Hirsutism was defined as a Ferriman-Gallwey score of 6 or more, menstrual/ovulatory dysfunction as a history of menstrual cycles of more than 35-day, and hyperandrogenemia as total or free T, A4, and/or dehydroepiandrosterone sulfate levels above the upper 95th percentile of control values. Further, defining functional androgen excess (FAE) as the presence of at least 2 of the 3 hyperandrogenic features, 4 of 38 (10.5%) of carriers appeared to be affected (95% confidence interval, 2.9-24.8%). Assuming an expected prevalence rate of FAE in the general population of 5-20%, the frequency of FAE among our carriers was not significantly higher than expected. In conclusion, heterozygosity for CYP21 mutations does not appear to increase the risk of clinically evident hyperandrogenism, although carrying the defect was associated with higher mean and free T levels. Finally, due to the low frequency of androgen excess in our heterozygote population, we were unable to correlate the severity of the CYP21 mutation and/or the 17-OHP response to ACTH stimulation with the presence of the phenotype.

Radioimmunoassay of three deoxycorticoids in human plasma following HPLC separation

A radioimmunoassay of three deoxycorticoids, namely 11 beta,17 alpha-dihydroxy-4-pregnene-3,20-dione (21-deoxycortisol), 17 alpha,21-dihydroxy-4-pregnene-3,20-dione (11-deoxycortisol), and 21-hydroxy-4-pregnene-3,20-dione (11-deoxycorticosterone) which are important for differential diagnosis of congenital adrenal disorders, is described and evaluated. Antisera against 3-(O-carboxymethyl)oximes conjugated to bovine serum albumin were raised in rabbits. The radioligands were prepared by radioiodination of previously synthesized homologous tyrosine methyl ester derivatives. Following diethyl ether extraction, the steroids were separated from each other and from cross-reactants by HPLC using a Nucleosil C8 reverse-phase column and a methanol-water mixture (7:5, v/v) as an eluent. Normal levels of analyzed steroids ranged from 0.02 to 0.348, 0.185 to 3.80, and 0.013 to 0.299 nmol/l, for 21-deoxycortisol, 11-deoxycortisol and 11-deoxycorticosterone, respectively. The levels of both deoxycortisols rose significantly after ACTH treatment. Data are given with respect to the concentrations of these steroids in some pathological situations such as 21-hydroxylase and 11 beta-hydroxylase block, hyperaldosteronism, and polycystic ovary syndrome.

Molecular detection of genetic defects in congenital adrenal hyperplasia due to 21-hydroxylase deficiency: a study of 27 families

Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase (21-OHase) deficiency is inherited as an autosomal recessive trait. Patients can present with the salt wasting, simple virilizing or a non-classical form of the disease. The gene for P450C21, the enzyme carrying 21-OHase activity, has been mapped to the major histocompatibility complex on chromosome 6p. Using molecular hybridisation techniques we have studied the genetic defect in 27 families with one or more affected offspring diagnosed and treated at the University Hospital of Essen. DNA samples were digested with restriction endonuclease TaqI, PvuII, BglII, and EcoRI and analysed by Southern blot hybridisation with the cDNA probe pC21/3c. Eleven of 40 haplotypes associated with the salt wasting form were found to have a large deletion of 30 kb affecting the 5' end of the active 21-OHase gene and the 3' end of the closely linked pseudogene. Results in another 11 cases are compatible with gene conversion; 18 cases were not informative. The 30 kb deletion was associated with a combination of the HLA antigens Bw47 and DR7 in 7 of 11 cases. In the haplotypes with gene conversion, no linkage disequilibrium to HLA antigens was found. No apparent gene alterations were detected in simple virilizing and non-classical haplotypes. The direct detection of the genetic defect in 55% of the salt wasting haplotypes may help to improve predictive testing in families with CAH.