Biomedical subjects

Charles Sultan

Publications and source records attributed to Charles Sultan.

At least 37 records · Page 2Linked to original sources

PubMed2004

Activating Gsalpha mutations: analysis of 113 patients with signs of McCune-Albright syndrome--a European Collaborative Study.

McCune-Albright syndrome (MAS) is a sporadic disorder characterized by the classic triad of polyostotic fibrous dysplasia, café-au-lait skin pigmentation, and peripheral precocious puberty. It is due to postzygotic activating mutations of arginine 201 in the guanine-nucleotide-binding protein (G protein) alpha-subunit (Gsalpha), leading to a mosaic distribution of cells bearing constitutively active adenylate cyclase. MAS is heterogeneous: beyond the classic triad, a number of atypical or partial presentations have been reported. We present here the results of a systematic search for Gsalpha mutations in patients presenting with at least one of the signs of MAS, using a PCR-based sensitive method. We studied 113 patients (98 girls and 15 boys), 24% presenting the classic triad, 33% with two signs, and 40% with only one classic sign. Overall, the mutation was identified in 43% of the patients. When an affected tissue was available, the mutation was found in more than 90% of the patients, whatever the number of signs. Skin was a noteworthy exception because only three of the 11 skin samples were positive. The mutation was detected in 46% of blood samples in patients presenting the classic triad, whereas this figure fell to 21% and 8% in patients with two and one sign, respectively. Our results highlight the frequency of partial forms of MAS and the usefulness of sensitive techniques to confirm the diagnosis at the molecular level. It should be emphasized that we found the mutation in 33% of the 39 cases of isolated peripheral precocious puberty. This study has further widened the definition of MAS. Affections as clinically different as monostotic fibrous dysplasia, isolated peripheral precocious puberty, neonatal liver cholestasis, and the classic MAS all appear to be components of a wide spectrum of diseases based on the same molecular defect.

Bone and Bones↗

PubMed2004

Management of infertility in a patient presenting with ovarian dysfunction and McCune-Albright syndrome.

Persistent autonomous ovarian dysfunction in McCune-Albright syndrome (MAS) patients is associated with the development of multiple dominant follicles, premature luteinization, cyst formation, and anovulatory infertility. Due to the mosaic distribution of the mutation, ovaries may be unequally affected. In the current patient, the least affected ovary became quiescent upon GnRH agonist-induced gonadotropin suppression. Normoovulatory cycles were restored after subsequent removal of the affected right ovary, and a pregnancy was established within 3 months. A healthy unaffected girl was born at term after an uneventful pregnancy. The placental tissue was normal, and the mutation was not detected in the placenta, umbilical cord structures, or umbilical cord blood. GnRH analog administration may help to identify those MAS patients who might benefit from unilateral ovariectomy. Because a healthy baby was born, evidence is provided suggesting that MAS is not passed on to the children from the parents.

Adult↗

PubMed2004

Interlaboratory comparison of four in vitro assays for assessing androgenic and antiandrogenic activity of environmental chemicals.

We evaluated and compared four in vitro assays to detect androgen agonists and antagonists in an international interlaboratory study. Laboratory 1 used a cell proliferation assay (assay 1) with human mammary carcinoma cells stably transfected with human androgen receptor. The other laboratories used reporter gene assays, two based on stably transfected human prostate carcinoma cells (assay 2) or human mammary carcinoma cells (assay 4), and the third based on transient transfection of Chinese hamster ovary cells (assay 3). Four laboratories received four coded compounds and two controls: two steroidal androgens, two antiandrogens, an androgenic control, 5alpha-dihydrotestosterone (DHT), and an antiandrogenic control, bicalutamide (ICI 176,334). All laboratories correctly detected the androgenic activity of 4-androsten-3,17-dione and 17alpha-methyltestosterone. For both compounds, the calculated androgenic potencies relative to the positive control (RAPs) remained within one order of magnitude. However, laboratory 3 calculated a 50-fold higher RAP for 4-androsten-3,17-dione. All assays detected and quantified the antiandrogenic effect of vinclozolin [median inhibitory concentration (IC50) values ranging from 1.1 times symbol 10(-7) M to 4.7 times symbol 10(-7) M]. In assays 2 and 3, vinclozolin showed partial androgenic activity at the highest concentrations tested. For vinclozolin, calculated antiandrogenic potencies relative to bicalutamide (RAAPs) differed no more than a factor of 10, and IC50 values matched those of bicalutamide. Similarly, we found antiandrogenic activity for tris-(4-chlorophenyl)methanol. RAAP values were between 0.086 and 0.37. Three assays showed cytotoxicity for this compound at or above 1 times symbol 10(-5) M. In summary, all assays proved sensitive screening tools to detect and quantify androgen receptor-mediated androgenic and antiandrogenic effects of these chemicals accurately, with coefficients of variation between 8 and 90%.

Androgen Antagonists↗

PubMed2004

An N-terminal WT1 mutation (P181S) in an XY patient with ambiguous genitalia, normal testosterone production, absence of kidney disease and associated heart defect: enlarging the phenotypic spectrum of WT1 defects.

OBJECTIVE: This study reports the clinical and molecular data of an XY patient with a very unusual phenotype due to a Wilms' tumor-suppressor (WT1) gene mutation. The genotype-phenotype relationship of different WT1 mutations is then discussed. PATIENT: The patient presented at birth with micropenis, severe hypospadias and cryptorchidism. Normal androgen production and an absence of clinical response to a testosterone treatment trial suggested partial androgen resistance. Eventually, female sex of rearing was chosen. At the beginning of puberty, normal male androgen production occurred, and subsequent gonadectomy did not show gonadal dysgenesis. It is notable that the patient, now 20 years of age, has not developed kidney disease. In addition to the genital malformation, the patient displayed an associated congenital heart defect, consisting of a coarctation of the aorta and a patent ductus arteriosis (PDA). RESULTS: No mutations were detected in the androgen receptor or 5alpha-reductase genes. Direct sequencing of the WT1 gene identified a heterozygous proline to serine substitution at position 181 (P181S). The same heterozygous mutation was found in the mother. Interestingly, the mother shows no signs of kidney disease at her present age of 49. CONCLUSION: This is the first germline missense mutation in the N-terminal part of WT1 identified in a patient with the very particular phenotype of ambiguous genitalia with absence of gonadal dysgenesis and kidney disease. The possible molecular mechanisms leading to the patient's phenotype are considered. The high frequency of PDA in newborns and the absence of heart abnormalities in XX females carrying the P181S mutation, however, suggest that the heart defect was most likely a coincidental association. This case enlarges the clinical spectrum of WT1 defects and may provide new insights into the complex functions of WT1 in genital and kidney development.

Aortic Coarctation↗

PubMed2003

Relationships between hormonal status and cataract in french postmenopausal women: the POLA study.

PURPOSE: Prevalence rate of cataract is higher in women than in men. Sex hormones have been hypothesized to be linked with this gender difference. Our aim is to study the relationships between hormonal status and cataract in postmenopausal women. METHODS: The Pathologies Oculaires Liées à l'Age (POLA) study is a population-based study on age-related eye diseases and their risk factors, in 2584 residents of Sète (France). Cataract classification was based on a standardized lens examination, according to Lens Opacities Classification System III. Biological measurements were performed from fasting blood samples. We conducted a cross-sectional study in the female participants (n=1451) aged over 60 years. RESULTS: No association of hormone replacement therapy (HRT) with any type of cataract was found, but an increased risk of cataract surgery was observed in women with a long duration of hormone therapy >/=5 years) (multivariate-adjusted odds ratio (OR)=3.80; 95% CI: 1.45-9.94). Globally, the risk for cataract (any type) was not associated with a long duration of HRT use (OR=1.06; 95% CI: 0.64-1.74). After multivariate adjustment, oophorectomy was associated with a reduced risk of cataract (OR=0.60; 95% CI=0.38-0.94). In the multivariate model, no association was found between estradiol, total testosterone or sex-hormone-binding globulin and cataract. However, high levels of dehydroepiandrosterone sulfate (DHEAS) were associated with a reduced risk of cataract (OR=0.79; 95% CI: 0.63-0.99). CONCLUSION: HRT use was not associated with cataract. A reduced risk of cataract was found in oophorectomized women and in women with high DHEAS levels.

Aged↗

PubMed2003

Molecular analysis of 5alpha-reductase type 2 gene in eight unrelated egyptian children with suspected 5alpha-reductase deficiency: prevalence of the G34R mutation.

OBJECTIVE: Analysis of the 5alpha-reductase type 2 (SRD5A2) gene in Egyptian patients with suspected 5alpha-reductase (5alphaR) deficiency. PATIENTS AND METHODS: Eight unrelated patients, originating from different geographical areas of Egypt, were referred to the Department of Pediatrics. Six prepubertal and two postpubertal patients presented with ambiguous genitalia. Four were being reared as females while the others were being reared as males. Six patients were products of consanguineous marriages. All patients had 46,XY karyotype. Basal and post-human chorionic gonadotrophin (hCG) stimulation plasma levels of testosterone and dihydrotestosterone were determined. Sequencing of five exons of the SRD5A2 gene was carried out. RESULTS: All patients had normal male testosterone levels, both basal and post-hCG stimulation. The T/DHT ratio was available for six patients and showed values that ranged from normal to high. Three different homozygous mutations were identified. One patient carried a Y235F substitution and two had a N160D substitution. Interestingly, all five of the other patients had the G34R mutation. The parents were heterozygous for the mutations, although the mother of one patient was homozygous for the G34R mutation. CONCLUSION: Among eight unrelated Egyptian children with 5alpha-reductase deficiency, the G34R mutation was identified in five patients. The high consanguinity rate in Egypt suggests a common ancestor with a founder gene effect in cases of G34R mutation.

Adolescent↗

PubMed2003

Mutation of the androgen receptor at amino acid 708 (Gly-->Ala) abolishes partial agonist activity of steroidal antiandrogens.

Mutation of a single amino acid in the ligand-binding domain (LBD) of the human androgen receptor (hAR) can induce functional abnormalities in androgen binding, stabilization of active conformation, or interaction with coactivators. The Gly708Ala and Gly708Val substitutions are associated with partial and complete androgen insensitivity syndromes, respectively. In this work, we introduced Ala, Val, and aromatic Phe mutations at position 708 on helix H3 of the hAR-LBD and tested the functional and structural consequences on hAR activity in the presence of steroidal or nonsteroidal agonists and antagonists. The residues involved in the specific recognition of these androgen ligands were identified and analyzed in the light of in vitro biological experiments and the 3D hAR-LBD structure. Our study demonstrated that the Gly708Ala mutation influenced the agonist versus antagonist activity of the ligands and confirmed the crucial role of this residue within the ligand-binding pocket (LBP) in the modulation of androgen agonists. The Gly708Ala mutation transformed the antiandrogen cyproterone acetate (CPA), a partial agonist, into a pure antiandrogen, and the pure nonsteroidal antiandrogen hydroxyflutamide in a partial agonist. From the docking studies, we suggest that CPA acts on AR through the novel mechanism called "passive antagonism".

Alanine↗

PubMed2003

A new mutation of 5-alpha-reductase type 2 (A62E) in a large Egyptian kindred.

OBJECTIVE: To describe the clinical, biological and molecular data in a large Egyptian kindred with 5alpha-reductase deficiency. PATIENTS AND METHODS: Three patients with ambiguous genitalia were referred at the ages of 20, 9 and 2 years, respectively. In all cases, parents were first cousins. Basal and post-HCG stimulation plasma levels of testosterone and dihydrotestosterone were determined. Direct sequencing and restriction site analysis were applied for patient and family study. RESULTS: A homozygous alanine to glutamic acid substitution at position 62 (A62E) was found in the three patients. The parents and two XX sisters were heterozygous while a third XX sibling was normal. CONCLUSION: We report a new mutation of the 5alpha-reductase type 2 gene. The presence of this mutation in all studied patients and their parents suggests its causative role in 5alpha-reductase deficiency. Identification of the mutation enabled genetic counselling for three XX individuals.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗

PubMed2003

A novel mutation of the 5alpha-reductase type 2 gene in two unrelated Egyptian children with ambiguous genitalia.

OBJECTIVE: To establish an etiological diagnosis in two unrelated Egyptian children with ambiguous genitalia through biochemical and molecular analyses. PATIENTS AND METHODS: Two XY patients were referred: one at the age of 14 years presenting with delayed puberty and menarche and the second at the age of 4 months with ambiguous genitalia. Basal and post-HCG stimulation plasma levels of testosterone (T) and dihydrotestosterone (DHT) were determined. Direct sequencing of the five exons of the 5alphaR type 2 gene and exons 2 to 8 of the androgen receptor gene was carried out. RESULTS: The high T/DHT value indicated 5alphaR deficiency in the first patient while the absence of parental consanguinity along with normal T/DHT value in the second patient suggested androgen insensitivity. In both patients, we identified a homozygous A --> G mutation in exon 3 that replaced the asparagine residue at position 160 by an aspartic acid. The parents of both patients were all heterozygotes for the N160D substitution. CONCLUSIONS: 1) We report a new mutation that enlarges the spectrum of genetic defects in 5alphaR deficiency. 2) Although the two patients were referred at very different ages, the clinical presentations raise the possibility of phenotypic variability for the same mutation. 3) These reports underline the difficulty of diagnosing 5alphaR deficiency based only on clinical and biochemical grounds. Molecular study remains the only definitive tool for diagnosis of ambiguous genitalia.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗

PubMed2002

Potential action of IGF-1 and EGF on androgen receptor nuclear transfer and transactivation in normal and cancer human prostate cell lines.

This work was designed to determine whether IGF-1 and EGF modulate nuclear transfer and transactivation of the androgen receptor (AR) in human prostate cell lines (PNT1A and DU-145). We first characterized the IGF-1 and EGF receptors by ligand-binding assays with [125I] IGF-1 and [125I] EGF in a normal human prostate epithelial cell line, PNT1A. We then evaluated the effects of these growth factors on AR nuclear transfer and transcriptional activation in this cell line and in DU-145, a human prostate tumor cell line. The cell lines were cotransfected with an AR expression vector and an androgen-responsive luciferase gene driven by the mouse mammary tumor virus (MMTV-luciferase) promoter. Neither IGF-1 nor EGF could activate reporter gene in the absence of androgens. Conversely, both enhanced the magnitude of the AR response in the presence of low levels of androgen (10(-11)-10(-9) M) and this response, increased by twofold, was inhibited by hydroxyflutamide. No effect of IGF-1 and EGF was observed on the intracellular localization of the fusion protein EGFP-AR in either cell line. The fluorescence stayed cytoplasmic even after 24 h of IGF-1 or EGF treatment. Taken together, these data indicate that growth factors are unable to initiate the nuclear translocation of AR in the absence of androgens or to induce ligand-independent transcriptional activity. We observed only cross-talk in the presence of androgens and IGF-1 or EGF, leading to an over-activated AR. In conclusion, the cross-talk between AR and growth factor signaling pathways may sensitize AR to suboptimal stimulation by low levels of androgens.

Active Transport, Cell Nucleus↗

PubMed2002

Evaluation of androgenic bioactivity in human serum by recombinant cell line: preliminary results.

Besides the measurement of circulating conjugated metabolites of dihydrotestosterone (DHT), which reflects androgenic activity, only one assay to measure androgenic bioactivity in human serum has been proposed thus far. This recombinant bioassay is based on the androgen-dependent interaction between the LBD and NT domains of AR fused to the Gal 4 DNA-binding domain, but its construction is highly complex. We have developed a mammalian cell (CHO 515) bioassay that measures total androgen bioactivity in human serum. The AR-deficient Chinese hamster ovary (CHO) cells were stably transfected with pSG5-puro-hAR and pMMTV-neo-Luc. After selection with puromycin and neomycin, five highly inducible clones were isolated and one was selected. The expression of human androgen receptor (hAR) was confirmed by Western blot and steroid-binding assays on the whole cells. The transcriptional activity of the clone was measured after 24 h of incubation with increasing concentrations of various androgenic and non-androgenic steroid compounds in a 96-well plate. The EC50s for each tested androgenic steroid compound were 4 x 10(-11) M, 1.5 x 10(-11) M, 1 x 10(-9) M, 2 x 10(-10) M, 3 x 10(-10) M for testosterone, DHT, dehydroepiandrosterone (DHEA), delta5-androstenediol, and delta4-androstenedione, respectively. In the physiological concentrations of the non-androgenic steroids, estradiol, cortisol, aldosterone, and progesterone, no interference was noted with the AR transactivation level. Evaluation of androgenic bioactivity in human serum was performed by incubation of CHO 515 cells with 100 microl of patient serum, diluted at 1/100 = 1% in DMEM-F12 without phenol red. The sensitivity of the assay was < 0.3 ng/ml. The mean androgenic bioactivity expressed in testosterone equivalents was 0.6 +/- 0.2 ng/ml in normal prepubertal boys, and 12.4 +/- 2 and 1.7 +/- 0.1 ng/ml in normal pubertal boys and girls, respectively. In conclusion, this new recombinant cell bioassay is today the only assay that takes into account testosterone, DHT, DHEA, delta5-androstenediol, and delta4-androstenedione. It should be of particular use in male children with cryptorchidism, delayed puberty or hypogonadotrophic hypogonadism, i.e., in pediatric patients with low androgen levels.

Androgens↗

PubMed2002

Evidence that chlormadinone acetate exhibits antiandrogenic activity in androgen-dependent cell line.

Chlormadinone acetate (CMA), like other 17-hydroxyprogesterone derivatives, is thought to be a potential antiandrogen on the basis of its effect on spontaneous benign prostatic hyperplasia (BPH) in dogs. This work was undertaken to find out whether CMA presents antiandrogen activity in human androgen-dependent cell line. For this purpose, we used PALM cells, the PC-3 cell line stably transfected with human androgen receptor and a luciferase gene under transcriptional control of MMTV. Potential antiandrogenic activity was compared with that of cyproterone acetate (CPA), a standard steroidal antiandrogen. Both compounds were tested in competitive binding assays at 37 degrees C in the presence of 1 nM of [3H] R1881, a synthetic and non-metabolizable androgen. Their impact on AR transcriptional activity was evaluated by the measure of luciferase activity in the presence of R1881 with increasing concentrations of CMA or CPA (10(-8)-10(-6) M). In whole cell binding assays, competitive studies revealed that the Ki for CMA was 3.3 +/- 1.5 x 10(-8) M (versus 7.2 +/- 1.3 x 10(-8) M for CPA). Inhibition of AR transcriptional activity was 40 +/- 5% for CMA (3 x 10(-7) M) versus 59 +/- 6% for CPA at the same concentration. Moreover, CMA caused a slower import of green fluorescent protein (GFP)-AR to the nuclei of COS-7 cells than R1881. These data show that CMA exerted a competitive binding for AR and significantly decreased the AR transcriptional activity. In conclusion, this synthetic progestin presents simultaneous antiandrogenic activity that could be helpful as a new therapeutic option in women with luteal defect along with clinical signs of hyperandrogenism.

Active Transport, Cell Nucleus↗

PubMed2002

Mechanism of antiandrogen action: key role of hsp90 in conformational change and transcriptional activity of the androgen receptor.

Activation of the androgen receptor (AR) is induced by ligand binding through conformational changes leading to control of gene expression. Antiandrogens compete with androgens for AR occupancy and subsequently block at least one step in AR action. Analysis of nuclear transfer kinetics using the GFP-AR fusion protein and partial proteolysis analysis provided evidence that the ligand-bound receptor was in equilibrium between at least two distinct conformations, leading to the production of 35 and 29 kDa trypsin-resistant fragments. It also indicated that this equilibrium may regulate the rate of nuclear transfer. The slowing of nuclear transfer by antiandrogens was correlated with the amount of receptor in conformation leading to the 35 kDa trypsin-resistant fragment. To establish the role of heat shock protein (hsp) 90 activity in antiandrogenic action, the effect of geldanamycin (GA) was evaluated in both in vitro assays and live cells. We demonstrated that in vitro hsp90s are required to stabilize the receptor in the inactive conformation and that hsp90 activity is involved in the integrity and nuclear transfer of agonist- and antagonist-bound AR. Furthermore, nuclear transfer is not the only step affected by GA since this compound was also active on a constitutively nuclear AR (GFP-NLS-AR). Hsp90 inactivation impedes interaction of androgen-bound GFP-NLS-AR with nuclear components and inhibits transcriptional activity. We conclude that hsp90s are required for the acquisition of active conformation in agonist-bound AR to regulate nuclear transfer, nuclear matrix binding, and transcriptional activity. Pure antiandrogens block the transconformational change of AR in an intermediary complex unable to acquire the active conformation and to dissociate the hsp90.

Active Transport, Cell Nucleus↗

PubMed2002

Phenylphenols, biphenols, bisphenol-A and 4-tert-octylphenol exhibit alpha and beta estrogen activities and antiandrogen activity in reporter cell lines.

We previously demonstrated the interactions of different chemical compounds with estrogen receptors ERalpha and ERbeta and the androgen receptor (AR) using different reporter cell lines. In this study, we characterize the ERalpha, ERbeta and AR activity of different biphenyls using the same tools. We provide evidence that several phenyl derivatives present both estrogenic and antiandrogenic activity. The extent of hydroxylation and the position of the hydroxyl function were important in determining their estrogenicity and antiandrogenicity. Of the tested compounds, bisphenol-A and 4,4' biphenol had very high estrogenic activity, although it was lower than that of the strong estrogenic alkylphenol, 4-tert-octylphenol. Bisphenol-A and 4,4' biphenol were able to activate ERs at concentrations lower than 1 microM, whereas the other compounds only activated at concentrations above 1 microM. Interestingly, 4,4' biphenol was a better agonist for ERbeta than for ERalpha. No androgenic activity was detected for any of these compounds. Bisphenol-A, 3-OH phenylphenol, 4-OH phenylphenol and 4,4' biphenol exhibited antiandrogenic activity close to that of 4-tert-octylphenol (IC(50) approximately 5 microM). In whole cell binding assays, these compounds displaced [3H] R1881 with Ki = 10 microM. Although these Ki values seem high in comparison with that of hydroxyflutamide (0.4 microM), one must keep in mind that environmental chemicals can accumulate in adipose tissues for several years. In conclusion, these environmental chemicals may have a negative impact on androgen action during fetal and post-natal life.

Androgen Receptor Antagonists↗

PubMed2002

Equilibrium binding assays reveal the elevated stoichiometry and salt dependence of the interaction between full-length human sex-determining region on the Y chromosome (SRY) and DNA.

In an effort to better define the molecular mechanism of the functional specificity of human sex-determining region on the Y chromosome (SRY), we have carried out equilibrium binding assays to study the interaction of the full-length bacterial-expressed protein with a DNA response element derived from the CD3epsilon gene enhancer. These assays are based on the observation of the fluorescence anisotropy of a fluorescein moiety covalently bound to the target oligonucleotide. The low anisotropy value due to the fast tumbling of the free oligonucleotide in solution increases substantially upon binding the protein to the labeled target DNA. Our results indicate that the full-length human wild-type SRY (SRY(WT)) forms a complex of high stoichiometry with its target DNA. Moreover, we have demonstrated a strong salt dependence of both the affinity and specificity of the interaction. We have also addressed the DNA bending properties of full-length human SRY(WT) in solution by fluorescence resonance energy transfer and revealed that maximal bending is achieved with a protein to DNA ratio significantly higher than the classical 1:1. Oligomerization thus appears, at least in vitro, to be tightly coupled to SRY-DNA interactions. Alteration of protein-protein interactions observed for the mutant protein SRY(Y129N), identified in a patient presenting with 46,XY sex reversal, suggests that oligomerization may play an important role in vivo as well.

DNA↗

PubMed2002

Ambiguous genitalia in the newborn.

Ambiguous genitalia in the newborn need immediate and rational management. This complex situation requires a strategy of clinical, hormonal, genetic, molecular, and radiographic investigation to determine the etiology of the intersex state and orient the therapeutic approach. Physical examination is key to diagnosis. Careful palpation to locate gonads at the genital folds or in the inguinal region provides the first element for diagnostic orientation. If gonads are absent, a diagnosis of female pseudohermaphroditism seems advisable; if gonads are palpated, a diagnosis of male pseudohermaphroditism is more appropriate. Karyotyping is systematic while polymerase chain reaction (PCR) analysis of the SRY gene provides information about the presence of a Y chromosome within 1 day. Hormonal investigation should be based on clinical and genetic orientation. Substantially elevated plasma 17-OH progesterone will confirm the diagnosis of congenital adrenal hyperplasia due to deficiency in 21-hydroxylase. Testicular stimulation with human chorionic gonadotropin (hCG) will determine the functional value of testicular tissue. Exploration of the genitourinary axis is principally carried out by ultrasound and genitography. By the end of these investigations, the medical team should be able to give a precise diagnosis. Female pseudohermaphroditism may be due to excess fetal androgens (congenital adrenal hyperplasia), increased androgen production of maternal origin, or placental androgen excess. In male pseudohermaphroditism, if testosterone rises normally after hCG stimulation, androgen resistance is indicated. If it does not rise after this test, either testicular dysgenesis or disturbance in testosterone biosynthesis may be responsible. The assignment of sex for rearing must be guided by the etiology of the genital malformation, the anatomic condition, and family considerations. In cases of female pseudohermaphroditism, the newborn should always be declared to be of female sex at birth. In cases of male pseudohermaphroditism, great care should be taken in the declaration of male sex: the potential for reconstructive surgery and the pubertal "programmed" response of the external genitalia to endogenous and exogenous testosterone are determinant. Management of ambiguous genitalia in the newborn requires an entire multidisciplinary team in every step of the diagnostic procedure, the choice of sex assignment, and the treatment strategy.

Disorders of Sex Development↗

PubMed2002

Disorders of androgen action.

Disorders of androgen action are the main cause of male pseudohermaphroditism and include 5alphaR deficiency and androgen receptor defects. 5alphaR deficiency is characterized by female genitalia with some degree of masculinization, clitoromegaly, and severely bifid scrotum corresponding to the so-called pseudovaginal perineoscrotal hypospadias. At the onset of puberty, increased muscle mass, development of pubic hair, and phallic growth are associated with the acquisition of male gender identity. Normal or increased levels of testosterone and an elevated testosterone-to-dihydrotestosterone ratio after human chorionic gonadotropin stimulation testing suggest 5alphareductase deficiency, and the diagnosis can be ascertained by identifying the mutation in the 5alphaR-2 gene. Whatever the patient's age at diagnosis, psychological evaluation with 5alphaRD is vital. Androgen receptor defects encompass two clinical expressions: the complete and partial androgen insensitivity syndromes. Complete androgen insensitivity syndrome should be suspected at birth in the presence of inguinal hernia in a girl without genital ambiguity. At puberty, the sign of alert is primary amenorrhea with normal female phenotype and harmonious mammary development but no pubic hair growth. Partial androgen insensitivity syndrome covers a wide spectrum of undervirilized phenotypes ranging from clitoromegaly at birth to infertile men. In all cases, complementary investigations should include plasma testosterone and luteinizing hormone as well as androgen-binding capacity in cultured genital skin fibroblasts. Diagnosis is confirmed by identification of the androgen receptor gene mutation. Although patients with complete androgen insensitivity syndrome are raised as females, patients with partial androgen insensitivity syndrome should be managed according to age at diagnosis, response to treatment with exogenous androgens, and the presence of an androgen gene mutation. Gonadectomy in complete androgen insensitivity syndrome should be performed before puberty, and androgen substitution may improve the development of external genitalia in some patients with partial androgen insensitivity syndrome. Psychological follow-up is necessary.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗

PubMed2002

Pathophysiology of androgen insensitivity syndromes: molecular and structural approaches of natural and engineered androgen receptor mutations at amino acid 743.

To decipher the clues of genotype-phenotype mapping in androgen insensitivity syndromes (AIS), we integrated clinical, molecular, and structural data in an investigation into the characteristics of androgen receptor (AR) ligand binding and activation. We looked for residues substituted in AIS that are conserved among the different AR species but that diverge in the other steroid receptors, thus suggesting a role in androgen binding specificity. Of the residues fitting these characteristics, we focused on the glycine at position 743, for which natural substitutions (glutamic acid and valine) have been associated with different androgen resistance phenotypes. The consequences of both substitutions were evaluated along with the minimal glycine to alanine mutation. The gradual impairment of binding and trans-activation efficiencies in AR mutants ranging from alanine to valine and subsequently glutamic acid were highlighted by in vitro experiments. Structural analyses showed the consequences of these substitutions at the atomic level and suggested a difference in local organization among the nuclear receptor superfamily. Overall, this integrative approach provides a useful tool for further investigations into the AR structure-function relationship in AIS.

Amino Acid Sequence↗