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Introduction: Partial androgen insensitivity syndrome (PAIS) is a rare condition that is reported to be commonly associated with gynecomastia in males., Objectives: To assess the management of gynecomastia in male PAIS., Materials and Methods: Retrospective review of males with PAIS over the age of 10 years in the I-DSD registry., Results: Of the 205 eligible cases, information was available for 57 from 13 centers. An androgen receptor gene variant was confirmed in 45 (79%) with a median age at first presentation of 1.0 year (range 0.1, 26.0). Of the 45 genetically confirmed cases, gynecomastia was present in 41 (91%) with a median age at the time of gynecomastia development of 13.5 years (11.0, 29.0). In the other 4 (9%) with no gynecomastia, the median age at last assessment was 15.7 years (10.6, 17.0). In 30 cases with information available, micropenis was present at the time of gynecomastia development in 23 (77%). Of the 35 with information available, 2 (6%) exhibited spontaneous resolution between the ages of 15 and 21 years and 25 (71%) had breast surgery at a median age of 15.7 years (14.0, 23.0). Of these 25, 9 (26%) had previously received medical therapy. The median clinician score of effectiveness for medical therapy was 3 (1, 8) compared to 10 (3, 10) for surgery (P < .0001). In 31 with information available, 13 (42%) had received psychology support., Conclusion: Gynecomastia is common in PAIS but not universal. Surgical management may be more effective than medical therapy, but there is a need for further standardized and systematic studies., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Endocrine Society.)

Context: Adrenocortical carcinomas are very rare malignancies in childhood associated with poor outcome in advanced disease. Most adrenocortical tumors (ACT) are functional, causing signs and symptoms of adrenal hormone excess. In most studies, endocrine manifestations were reported 4 to 6 months prior to diagnosis., Objective: We sought to extend knowledge on endocrine manifestations with regard to age and sex to facilitate early diagnosis., Methods: We retrospectively analyzed features of adrenal hormone excess in children and adolescents with ACT registered with the GPOH-MET studies between 1997 and 2022. Stage of puberty was defined as prepubertal in females < 8 years of age and males < 9 years., Results: By December 2022, 155 patients (110 female, 45 male) with data on endocrine manifestations had been reported. Median age at ACT diagnosis was 4.2 years [0.1-17.8], median interval from first symptoms was 4.2 months [0-90.7]. In 63 girls of prepubertal age, the most frequently reported manifestations were pubarche (68.3%), clitoral hypertrophy (49.2%), and weight gain (31.7%); in 47 pubertal female patients, the most frequent manifestations were excessive pubic hair (46.8%), acne (36.2%), and hypertension (36.2%). Leading symptoms in 34 boys of prepubertal age were pubarche (55.9%), penile growth (47.1%), and acne (32.4%), while in 11 pubertal male patients, leading symptoms were weight gain (45.5%), hypertension (36.4%), excessive pubic hair (27.3%), and cushingoid appearance (27.3%). In pubertal patients, symptoms of androgen excess were mainly unrecognized as part of pubertal development, while symptoms of Cushing syndrome were more frequently apparent., Conclusion: The endocrine phenotype induced by pediatric ACT is age- and sex-dependent., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Context: Low birthweight (bw) and unfavorable intrauterine conditions have been associated with metabolic sequelae in later life, but little is known about their impact on glucocorticoid metabolism., Objective: We studied monozygotic twins with intratwin bw differences to analyze the long-term impact of bw on glucocorticoid metabolism., Methods: 46 monozygotic twin pairs with bw differences of <1 SDS (concordant; n = 29) and ≥1 SDS (discordant; n = 17) were recruited. At 6.9 years (mean age), saliva samples were collected (at 7 hours, 13 hours, 18 hours and 21 hour) and analyzed with liquid chromatography-tandem mass spectrometry (LC-MS/MS)., Results: We found significant or highly significant intratwin correlations in all twin pairs at 3 of 4 (cortisol), and 4 of 4 (cortisone) time points. Graphic evaluation of the diurnal cortisol patterns for each twin pair showed a distinct alignment in all groups. Analyses of the change of intratwin differences over the day by mixed linear modeling showed no intratwin differences in diurnal patterns. Regression analyses of intratwin differences at 7:00 hours showed a significant influence of catch-up growth, indicating lower cortisol concentrations in smaller twins with more catch-up growth (adj. R2 = 0.159, P = .014, ß = -3.71, F(1,42) = 9.15, f2 = 0.19)., Conclusion: In monozygotic twins with intratwin bw differences, intratwin catch-up growth showed a moderate influence on intratwin differences in morning cortisol concentrations. We observed no differences regarding diurnal patterns. In contrast, in all groups, we found significant intratwin correlations for cortisol and cortisone over the day and a pronounced graphic alignment of cortisol diurnal patterns. We therefore suggest a predominant significance of the genetic background compared with bw differences on cortisol metabolism., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Content: Gynecomastia (defined by proliferation of glandular elements) and pseudogynecomastia (defined by adipose tissue) are frequent in pubertal boys. An association with sex hormones and the growth hormone axis has been discussed., Objective: The objective of this work is to compare sex hormones, insulin-like growth factor 1 (IGF-1), and insulin-like growth factor binding protein 3 (IGFBP-3) between boys with gynecomastia and pseudogynecomastia (separation by ultrasound)., Design: An observational study was performed., Setting: The setting of this study was an outpatient clinic., Participants: A total of 124 pubertal boys (mean age 14 ± 2 years) with breast enlargement and 84 healthy boys (mean age 14 ± 2 years) without breast enlargement participated in this study., Interventions: No interventions were performed., Main Outcome Measures: Measurements were taken for sex hormones (progesterone, estradiol [E2], estriol, estrone, androstendione, testosterone [T], dihydrotestosterone) measured by liquid chromatography-tandem mass spectrometry, as well as gonadotropins, prolactin, IGF-1, and IGFBP-3., Results: Eighty-six boys suffered from gynecomastia and 38 from pseudogynecomastia. In boys with gynecomastia, the E2/T ratio (median 22, interquartile range [IQR] 8-75) was significantly (P < .05) higher compared to boys with pseudogynecomastia (median 12, IQR 5-21) or healthy controls without breast enlargement (median 18, IQR 6-44) even after adjustment for testes volume. T concentrations were significantly (P < .05) lower in boys with gynecomastia (median 1.8, IQR 0.7-4.2 nM/L) compared to boys with pseudogynecomastia (median 4.3, IQR 1.4-6.9 nM/L) or healthy controls without breast enlargement (median 3.1, IQR 0.6-7.6 nM/L). Boys with gynecomastia did not differ from boys with pseudogynecomastia according to other sex hormones, prolactin, IGF-1, or IGFBP-3 concentrations., Conclusions: True gynecomastia is characterized by a relative T deficiency to E2 concentrations in contrast to pseudogynecomastia., (© Endocrine Society 2020. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Context: Larger studies on outcomes in males with 45,X/46,XY mosaicism are rare., Objective: To compare health outcomes in males with 45,X/46,XY diagnosed as a result of either genital abnormalities at birth or nongenital reasons later in life., Design: A retrospective, multicenter study., Setting: Sixteen tertiary centers., Patients or Other Participants: Sixty-three males older than 13 years with 45,X/46,XY mosaicism., Main Outcome Measures: Health outcomes, such as genital phenotype, gonadal function, growth, comorbidities, fertility, and gonadal histology, including risk of neoplasia., Results: Thirty-five patients were in the genital group and 28 in the nongenital. Eighty percent of all patients experienced spontaneous pubertal onset, significantly more in the nongenital group (P = 0.023). Patients were significantly shorter in the genital group with median adult heights of 156.7 cm and 164.5 cm, respectively (P = 0.016). Twenty-seven percent of patients received recombinant human GH. Forty-four patients had gonadal histology evaluated. Germ cells were detected in 42%. Neoplasia in situ was found in five patients. Twenty-five percent had focal spermatogenesis, and another 25.0% had arrested spermatogenesis. Fourteen out of 17 (82%) with semen analyses were azoospermic; three had motile sperm., Conclusion: Patients diagnosed as a result of genital abnormalities have poorer health outcomes than those diagnosed as a result of nongenital reasons. Most patients, however, have relatively good endocrine gonadal function, but most are also short statured. Patients have a risk of gonadal neoplasia, and most are azoospermic, but almost one-half of patients has germ cells present histologically and up to one-quarter has focal spermatogenesis, providing hope for fertility treatment options., (Copyright © 2019 Endocrine Society.)

Context: Molecular mechanisms causing the broad phenotypic diversity of external masculinization in individuals with 45,X/46,XY mosaicism are poorly understood., Objective: Analysis of androgen receptor (AR) expression and function as a putative influencing factor for the genital phenotype in patients with 45,X/46,XY mosaicism., Design: Measurement of AR mRNA expression levels, AR activity [DHT-mediated APOD (apolipoprotein D) induction] and cellular 45,X/46,XY ratios in genital skin fibroblasts from individuals with 45,X/46,XY mosaicism and male reference individuals, and determination of the external virilization scale from individuals with 45,X/46,XY mosaicism., Setting: University hospital endocrine research laboratory. Patients or Other Participants: 30 genital skin fibroblast cultures (GFs) from male reference individuals and 15 GFs from individuals with 45,X/46,XY mosaicism., Intervention: None., Main Outcome Measures: Determination of AR mRNA expression and AR activity in male reference GFs and 45,X/46,XY GFs and correlation of the obtained data with the cellular 45,X/46,XY ratios and the patients' external virilization scale., Results: In 6 of 15 45,X/46,XY GFs, AR mRNA expression and AR activity were significantly lower compared with those in the 46,XY reference GFs. In this subgroup of reduced AR mRNA expression, a positive trend was seen between AR mRNA expression and the percentage of XY-positive cells. Furthermore, we found a positive correlation between AR activity and the external virilization scale in the 15 45,X/46,XY GF samples (P = 0.03)., Conclusion: Our results suggest that AR expression and AR activity might influence the phenotypic variability seen in patients with 45,X/46,XY mosaicism., (Copyright © 2019 Endocrine Society.)

Context: Inactivating mutations within the AR gene are present in only ~40% of individuals with clinically and hormonally diagnosed androgen insensitivity syndrome (AIS). Previous studies revealed the existence of an AR gene mutation-negative group of patients with AIS who have compromised androgen receptor (AR) function (AIS type II)., Objective: To investigate whether AIS type II can be due to epigenetic repression of AR transcription., Design: Quantification of AR mRNA and AR proximal promoter CpG methylation levels in genital skin-derived fibroblasts (GFs) derived from patients with AIS type II and control individuals., Setting: University hospital endocrine research laboratory., Patients: GFs from control individuals (n = 11) and patients with AIS type II (n = 14)., Main Outcome Measure(s): Measurement of AR mRNA and AR promoter CpG methylation as well as activity of AR proximal promoter in vitro., Results: Fifty-seven percent of individuals with AIS type II (n = 8) showed a reduced AR mRNA expression in their GFs. A significant inverse correlation was shown between AR mRNA abundance and methylation at two consecutive CpGs within the proximal AR promoter. Methylation of a 158-bp-long region containing these CpGs was sufficient to severely reduce reporter gene expression. This region was bound by the runt related transcription factor 1 (RUNX1). Ectopic expression of RUNX1 in HEK293T cells was able to inhibit reporter gene expression through this region., Conclusions: Aberrant CpGs methylation within the proximal AR promoter plays an important role in the control of AR gene expression and may result in AIS type II. We suggest that transcriptional modifiers, such as RUNX1, could play roles therein offering new perspectives for understanding androgen-mediated endocrine diseases.

Context: It is well established that boys are heavier than girls at birth. Although the cause of birth weight (BW) difference is unknown, it has been proposed that it could be generated from prenatal androgen action., Objective: The aim of the current study was to determine the BW of children with disorders of sex development (DSD) of different etiologies and to evaluate the effects of androgen action on BW., Methods: Data regarding diagnosis, BW, gestational age, karyotype, and concomitant conditions were collected from the International Disorders of Sex Development (I-DSD) Registry (www.i-dsd). BW standard deviation score was calculated according to gestational age. Cases were evaluated according to disorder classification in I-DSD (i.e., disorders of gonadal development, androgen excess, androgen synthesis, androgen action, nonspecific disorder of undermasculinization groups, and Leydig cell defect)., Results: A total of 533 cases were available; 400 (75%) cases were 46,XY, and 133 (25%) cases were 46,XX. Eighty cases (15%) were born small for gestational age (SGA). Frequency of SGA was higher in the 46,XY group (17.8%) than in the 46,XX (6.7%) group (P = 0.001). Mean BW standard deviation scores of cases with androgen excess and androgen deficiency [in disorders of gonadal development, androgen synthesis, and Leydig cell defect groups and androgen receptor gene (AR) mutation-positive cases in disorders of androgen action groups] were similar to normal children with the same karyotype. SGA birth frequency was higher in the AR mutation-negative cases in disorders of androgen action group and in the nonspecific disorders of the undermasculinization group., Conclusions: BW dimorphism is unlikely to be explained by fetal androgen action per se. 46,XY DSDs due to nonspecific disorders of undermasculinization are more frequently associated with fetal growth restriction, SGA, and concomitant conditions., (Copyright © 2017 by the Endocrine Society)

Background: Dehydroepiandrosterone sulfate (DHEAS) and 17-hydroxypregnenolone (17OHPreg) are important for understanding the Δ5 pathway (e.g., in adrenarche and obesity). Although mass spectrometry has become the state-of-the-art method for quantifying steroids, there are few comprehensive age-, sex-, and pubertal stage-specific reference ranges for children., Aims: To develop a sensitive and reliable ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for simultaneous quantification of DHEAS and 17OHPreg and to establish entire age-, sex- and pubertal stage-specific reference ranges in children., Methods: A total of 684 children, 453 (243 female, 210 male) with normal body mass index (BMI; <90th) and 231 (132 female, 99 male) obese subjects (>97th), were categorized into 11 age groups, and age- and Tanner stage (PH)-specific reference ranges were determined., Results: The limit of detection was 0.05 nmol/L for 17OHPreg and 0.5 nmol/L for DHEAS. Levels of both steroids declined after the neonatal period. Comparisons with RIA assays (Siemens, Munich, Germany) (DHEAS) and an in-house kit (17OHPreg) revealed 0.95 and 0.93, respectively, as coefficients of determination. Although DHEAS-generally higher in boys-increased continuously starting at 3 to 6 years, 17OHPreg remained largely constant. In obese patients, both were significantly elevated, also in part after alignment to Tanner stages (PH)., Conclusions: UPLC-MS/MS is sensitive and reliable for quantifying DHEAS and 17OHPreg. Our data support differential maturation of CYP17 during adrenarche with successively increasing 17,20-lyase activity but largely constant 17α-hydroxylation activity. Endocrine interpretation of 17OHPreg and DHEAS must consider differential patterns for age, sex, pubertal stage, and BMI., (Copyright © 2017 by the Endocrine Society)

Context: Clinical features of Metabolic Syndrome (MetS) and Cushing's Syndrome are similar, suggesting a pathogenetic role of hypothalamus-pituitary-adrenal axis in MetS., Objective: The aim of the study was to determine whether MetS diagnosis and specific clusters of MetS components (waist circumference, dyslipidemia, hypertension, and impaired glucose metabolism) are associated with serum cortisol (SC) or 24-h urinary free cortisol (UFC) levels., Design and Setting: We conducted cross-sectional analyses of data from our obesity cohort. We studied 264 obese children (age, 11.0 ± 2.8 years; male, 48%; BMI, 28.2 ± 5.4 kg/m(2)). We examined UFC, SC, homeostasis model assessment (HOMA), and features of MetS (waist circumference, blood pressure, fasting lipids, and glucose)., Results: Slightly increased UFC concentrations were measured in 30.7% of the children. Obese children with MetS had significantly (P = .003) higher UFC levels compared with obese children without MetS. Girls demonstrated significantly higher UFC concentrations compared with boys independent of pubertal stage. UFC and SC levels were significantly related to features of MetS, but the associations were stronger for UFC. In multivariate analyses adjusted for age, sex, and body mass index, none of the features of MetS but HOMA index was correlated with UFC, whereas SC demonstrated no significant association to any parameter of MetS or HOMA., Conclusions: Our findings support the hypothesis that changes in the hypothalamus-pituitary-adrenal axis are related to MetS in obesity. UFC seems to be a suitable marker for this relationship. Norm values for UFC adapted to obese children may help to avoid unnecessary dexamethasone suppression tests.

Context: The focus of care in disorders of sex development (DSD) is often directed to issues related to sex and gender development. In addition, the molecular etiology remains unclear in the majority of cases., Objective: To report the range of associated conditions identified in the international DSD (I-DSD) Registry., Design, Setting, and Patients: Anonymized data were extracted from the I-DSD Registry for diagnosis, karyotype, sex of rearing, genetic investigations, and associated anomalies. If necessary, clarification was sought from the reporting clinician., Results: Of 649 accessible cases, associated conditions occurred in 168 (26%); 103 (61%) cases had one condition, 31 (18%) had two conditions, 20 (12%) had three conditions, and 14 (8%) had four or more conditions. Karyotypes with most frequently reported associations included 45,X with 6 of 8 affected cases (75%), 45,X/46,XY with 19 of 42 cases (45%), 46,XY with 112 of 460 cases (24%), and 46,XX with 27 of 121 cases (22%). In the 112 cases of 46,XY DSD, the commonest conditions included small for gestational age in 26 (23%), cardiac anomalies in 22 (20%), and central nervous system disorders in 22 (20%), whereas in the 27 cases of 46,XX DSD, skeletal and renal anomalies were commonest at 12 (44%) and 8 (30%), respectively. Of 170 cases of suspected androgen insensitivity syndrome, 19 (11%) had reported anomalies and 9 of these had confirmed androgen receptor mutations., Conclusions: Over a quarter of the cases in the I-DSD Registry have an additional condition. These associations can direct investigators toward novel genetic etiology and also highlight the need for more holistic care of the affected person.

Context: Little information is available on the steroid hormone profiles in obese children and their changes after weight loss., Objective: We compared liquid chromatography-tandem mass spectrometry of serum steroid hormone profiles between obese and normal-weight children and studied the differential effects of weight loss on these hormones., Design: This study was a cross-sectional comparison between obese and normal-weight children and a longitudinal 1-year follow-up study during lifestyle intervention in obese children., Setting: The setting of the study was primary care., Patients: Forty obese prepubertal (mean age 8.5 ± 2.1 years, 48% female, mean body mass index 24.8 ± 3.5 kg/m(2)) and 40 normal-weight children matched for gender, age, and pubertal stage., Intervention: The study consisted of an outpatient 1-year intervention program based on exercise, behavior, and nutrition therapy., Main Outcomes Measures: Progesterone, 17-hydroxyprogesterone, 11-deoxycorticosterone, corticosterone, aldosterone, 11-deoxycortisol, cortisol, cortisone, dehydroepiandrosterone sulfate (DHEAS), androstenedione, T, dihydrotestosterone, insulin resistance index of the homeostasis model assessment, and blood pressure were measured., Results: Prepubertal obese children showed significantly increased androgens (DHEAS, androstenedione, T), mineralocorticoid precursor corticosterone, and glucocorticoids (11-deoxycortisol, cortisol, cortisone) compared with normal-weight children. In contrast to 20 obese children without weight loss, the 20 obese children with substantial weight loss demonstrated a significant decrease of cortisol, cortisone, and corticosterone. Androstenedione and T decreased but DHEAS remained elevated. Changes of the homeostasis model assessment correlated significantly positively with changes of cortisol (r = 0.38) and cortisone (r = 0.43) in partial regression analyses adjusted to changes of weight status., Conclusions: In obese prepubertal children, the increased androgens, mineralocorticoid precursors, and glucocorticoids were responsive to weight loss in contrast to DHEAS, suggesting that DHEAS does not seem to be regulated by changes in body mass index.

Context: Acrodysostosis is a rare skeletal dysplasia that is associated with multiple resistance to G protein-coupled receptor (GPCR) signaling hormones in a subset of patients. Acrodysostosis is genetically heterogeneous because it results from heterozygous mutations in PRKAR1A or PDE4D, two key actors in the GPCR-cAMP-protein kinase A pathway., Objective: Our objective was to identify the phenotypic features that distinguish the two genotypes causing acrodysostosis., Patients and Methods: Sixteen unrelated patients with acrodysostosis underwent a candidate-gene approach and were investigated for phenotypic features., Results: All patients had heterozygous de novo mutations. Fourteen patients carried a PRKAR1A mutation (PRKAR1A patients), five each a novel PRKAR1A mutation (p.Q285R, p.G289E, p.A328V, p.R335L, or p.Q372X), nine the reported PRKAR1A p.R368X mutation; two patients harbored a mutation in PDE4D (PDE4D patients) (one novel mutation, p.A227S; one reported, p.E590A). All PRKAR1A, but none of the PDE4D mutated patients were resistant to PTH and TSH. Two PRKAR1A patients each with a novel mutation presented a specific pattern of brachydactyly. One PDE4D patient presented with acroskyphodysplasia. Additional phenotypic differences included mental retardation in PDE4D patients. In addition, we report the presence of pigmented skin lesions in PRKAR1A and PDE4D patients, a feature not yet described in the acrodysostosis entity., Conclusions: All PRKAR1A and PDE4D patients present similar bone dysplasia characterizing acrodysostosis. Phenotypic differences, including the presence of resistance to GPCR-cAMP signaling hormones in PRKAR1A but not PDE4D patients, indicate phenotype-genotype correlations and highlight the specific contributions of PRKAR1A and PDE4D in cAMP signaling in different tissues.

Context: The steroidogenic acute regulatory protein (StAR) has been shown to be essential for steroidogenesis by mediating cholesterol transfer into mitochondria. Inactivating StAR mutations cause the typical clinical picture of congenital lipoid adrenal hyperplasia., Objective: The objective of the investigation was to study the functional and structural consequences of three novel StAR mutations (p.N148K in an Italian patient; p.P129fs and p.Q128R in a Turkish patient)., Methods and Results: Transient in vitro expression of the mutant proteins together with P450 side-chain cleavage enzyme, adrenodoxin, and adrenodoxin reductase yielded severely diminished cholesterol conversion of the p.N148K mutant, the combined p.P129fs and p.Q128R mutant, and the p.P129fs mutant by itself. The p.Q128R mutant led to a higher cholesterol conversion than the wild-type StAR protein. As derived from three-dimensional protein modeling, the residue N148 is lining the ligand cavity of StAR. A positively charged lysine residue at position 148 disturbs the hydrophobic cluster formed by the alpha4-helix and the sterol binding pocket. The frame shift mutation p.P129fs truncates the StAR protein. Residue p.Q128 is situated at the surface of the molecule and is not part of any functionally characterized region of the protein., Conclusion: The mutations p.N148K and p.P129fs cause adrenal insufficiency in both cases and lead to a disorder of sex development with complete sex reversal in the 46, XY case. The mutation p.Q128R, which is not relevant for the patient's phenotype, is the first reported variant showing a gain of function. We speculate that the substitution of hydrophilic glutamine with basic arginine at the surface of the molecule may accelerate cholesterol transfer.

Background: Congenital adrenal hyperplasia is caused by insufficient adrenal steroid biosynthesis due to impaired steroidogenic enzymes. The majority of patients suffer from deficiency of 21-hydroxylase (CYP21) coded by the CYP21A2 gene., Objective: Our objective was to study the functional and structural consequences of the novel CYP21A2 missense mutation c.364A > C (K121Q) detected in a female patient with nonclassical 21-hydroxylase deficiency. The patient was compound heterozygous for the novel K121Q mutation and the mild P453S mutation., Results: In vitro expression analysis of the mutant K121Q enzyme in transiently transfected COS-7 cells revealed reduced CYP21 activity of 14.0 +/- 5% for the conversion of 17-hydroxyprogesterone and 19.5 +/- 4% for the conversion of progesterone. K121 is located on helix C in the CYP21 protein, which is part of the heme coordinating system. In addition, helix C is involved in the interaction with the electron-providing enzyme P450 oxidoreductase. Protein modeling revealed that the substitution of glutamine for the basic amino acid lysine introduces an electrostatic change on the surface of CYP21 and may additionally change heme coordination. We hypothesize that the electron flux between P450 oxidoreductase and CYP21 is impaired and, moreover, that substrate affinity is altered due to heme dislocation with K121Q., Conclusion: Both the interaction of P450 oxidoreductase and CYP21 as well as heme coordination are likely to be disturbed due to the K121Q mutation. Our data exemplify how the combination of in vitro expression and structural protein analysis provide novel insights into molecular mechanisms of reduced CYP21 activity, eventually explaining the patient's phenotype.

Introduction: 3beta-Hydroxysteroid dehydrogenase (3beta-HSD) deficiency is a rare cause of congenital adrenal hyperplasia caused by inactivating mutations in the HSD3B2 gene. Most mutations are located within domains regarded crucial for enzyme function. The function of the C terminus of the 3beta-HSD protein is not known., Objective: We studied the functional consequences of three novel C-terminal mutations in the 3beta-HSD protein (p.P341L, p.R335X and p.W355X), detected in unrelated 46,XY neonates with classical 3beta-HSD type II deficiency showing different degrees of under-virilization., Methods and Results: In vitro expression of the two truncated mutant proteins yielded absent conversion of pregnenolone and dehydroepiandrosterone (DHEA), whereas the missense mutation p.P341L showed a residual DHEA conversion of 6% of wild-type activity. Additional analysis of p.P341L, including three-dimensional protein modeling, revealed that the mutant's inactivity predominantly originates from a putative structural alteration of the 3beta-HSD protein and is further aggravated by increased protein degradation. The stop mutations cause truncated proteins missing the final G-helix that abolishes enzymatic activity irrespective of an augmented protein degradation. Genital appearance did not correlate with the mutants' residual in vitro activity., Conclusions: Three novel C-terminal mutants of the HSD3B2 gene are responsible for classical 3beta-HSD deficiency. The C terminus is essential for the enzymatic activity. However, more studies are needed to clarify the exact function of this part of the protein. Our results indicate that the genital phenotype in 3beta-HSD deficiency cannot be predicted from in vitro 3beta-HSD function alone.

Background: Sufficient androgen receptor (AR) activity is crucial for normal male sexual differentiation. Here we report on two unrelated 46, XY patients suffering from undervirilization and genital malformations. Both patients had a short polyglycine (polyG) repeat of 10 residues and a relatively long polyglutamine (polyQ) repeat of 28 and 30 residues within the transactivation domain of the AR. In addition, they also harbor a rare A645D substitution., Objective: We made a set of AR expression plasmid constructs with varying polyQ and polyG tract sizes in context with or without the A645D substitution and analyzed their in vitro transactivation capacity in transfected CHO cells., Results: We found that a short polyG repeat downmodulated AR activity to approximately 60-65% of the wild-type receptor. This effect was aggravated by A645D in context of a long polyQ repeat to less than 50% activity. In contrast, in the context of a short polyQ and a short polyG repeat, the A645D mutation rescues AR activity to almost wild-type levels, demonstrating a contradictory effect of this mutation, depending on the size of the polymorphic repeats., Conclusions: A combination of a short polyG repeat with a long polyQ repeat and an A645D substitution might contribute to the development of virilization disorders and explain the observed phenotypes of our patients as a form of androgen insensitivity. The whole recreation of AR sequence variations including individual polymorphic repeat sizes could unravel possible interference of mutations and variations on AR activity by in vitro transfection.

Context: Congenital adrenal hyperplasia is a group of autosomal recessive inherited disorders of steroidogenesis. The deficiency of steroid 11-hydroxylase (CYP11B1) resulting from mutations in the CYP11B1 gene is the second most frequent cause., Objective: We studied the functional and structural consequences of two CYP11B1 missense mutations, which were detected in a 1.8-yr-old boy with acne and precocious pseudopuberty, to prove their clinical relevance and study their impact on CYP11B1 function., Results: The in vitro expression studies in COS-7 cells revealed an almost complete absence of CYP11B1 activity for the P94L mutant to 0.05% for the conversion of 11-deoxycortisol to cortisol. The A368D mutant severely reduced the CYP11B1 enzymatic activity to 1.17%. Intracellular localization studies by immunofluorescence revealed that the mutants were correctly localized. Introducing these mutations in a three-dimensional model structure of the CYP11B1 protein provides a possible explanation for the effects measured in vitro. We hypothesize that the A368D mutation interferes with structures important for substrate specificity and heme iron binding, thus explaining its major functional impact. However, according to structural analysis, we would expect only a minor effect of the P94L mutant on 11-hydroxylase activity, which contrasts with the observed major effect of this mutation both in vitro and in vivo., Conclusion: Analyzing the in vitro enzyme function is a complementary procedure to genotyping and a valuable tool for understanding the clinical phenotype of 11-hydroxylase deficiency. This is the basis for accurate genetic counseling, prenatal diagnosis, and treatment. Moreover, the combination of in vitro enzyme function and molecular modeling provides valuable insights in cytochrome P450 structural-functional relationships, although one must be aware of the limitations of in silico-based methods.

Disruption of the P450 side-chain cleavage cytochrome (P450scc) enzyme due to deleterious mutations of the CYP11A1 gene is thought to be incompatible with fetal survival because of impaired progesterone production by the fetoplacental unit. We present a 46,XY patient with a homozygous disruption of CYP11A1. The child was born prematurely with complete sex reversal and severe adrenal insufficiency. Laboratory data showed diminished or absent steroidogenesis in all pathways. Molecular genetic analysis of the CYP11A1 gene revealed a homozygous single nucleotide deletion leading to a premature termination at codon position 288. This mutation will delete highly conserved regions of the P450scc enzyme and thus is predicted to lead to a nonfunctional protein. Both healthy parents were heterozygous for this mutation. Our report demonstrates that severe disruption of P450scc can be compatible with survival in rare instances. Furthermore, defects in this enzyme are inherited in an autosomal-recessive fashion, and heterozygote carriers can be healthy and fertile. The possibility of P450scc-independent pathways of steroid synthesis in addition to the current concept of luteoplacental shift of progesterone synthesis in humans has to be questioned.