Nadège Servant

Phenotypical, Biological, and Molecular Heterogeneity of 5α-Reductase Deficiency: An Extensive International Experience of 55 Patients

CONTEXT In 46,XY disorders of sex development, 5α-reductase deficiency is rare and is not usually the first-intention diagnosis in newborn ambiguous genitalia, contrary to partial androgen insensitivity syndrome. Yet the cause of ambiguous genitalia may guide sex assignment, and rapid, precise diagnosis of 5α-reductase deficiency is essential. OBJECTIVE The aim of the study was to describe relevant data for clinical diagnosis, biological investigation, and molecular determination from 55 patients with srd5A2 mutations identified in our laboratory over 20 yr to improve early diagnosis. SETTING The study was performed at Montpellier University Hospital. PATIENTS We studied a cohort of 55 patients with srd5A2 gene mutations. MAIN OUTCOME MEASURE(S) Genetic analysis of srd5A2 was conducted. RESULTS Clitoromegaly (49.1%) and microphallus with various degrees of hypospadias (32.7%) were frequent phenotypes. Female external genitalia (7.3%) and isolated micropenis (3.6%) were rare. Seventy-two percent of patients were initially assigned to female gender; five of them (12.5%) switched to male sex in peripuberty. Over 72% of patients were considered for 5α-reductase deficiency diagnosis when the testosterone/dihydrotestosterone cutoff was 10. In 55 patients (with 20 having a history of consanguinity), we identified 33 different mutations. Five have never been reported: p.G32S, p.Y91H, p.G104E, p.F223S, and c.461delT. Homozygous mutations were present in 69.1% of cases, compound heterozygous mutations in 25.5%, and compound heterozygous mutations alone with the V89L polymorphism in 5.4%. Exons 1 and 4 were most affected, with 35.8 and 21.7% mutant alleles per exon, respectively. CONCLUSIONS In the largest cohort to date, we demonstrate a wide spectrum of phenotypes and biological profiles in patients with 5α-reductase deficiency, whatever their geographical or ethnic origins.

Steroidogenic factor-1 (SF-1) gene mutation as a frequent cause of primary amenorrhea in 46,XY female adolescents with low testosterone concentration

BackgroundPrimary amenorrhea due to 46,XY disorders of sex differentiation (DSD) is a frequent reason for consultation in endocrine and gynecology clinics. Among the genetic causes of low-testosterone primary amenorrhea due to 46,XY DSD, SRY gene is reported to be frequently involved, but other genes, such as SF1 and WT1, have never been studied for their prevalence.MethodsWe directly sequenced SRY, SF1 and WT1 genes in 15 adolescent girls with primary amenorrhea, low testosterone concentration, and XY karyotype, to determine the prevalence of mutations. We also analyzed the LH receptor gene in patients with high LH and normal FSH concentrations.ResultsAmong the 15 adolescents with primary amenorrhea and low testosterone concentration, we identified two new SRY mutations, five new SF1 mutations and one new LH receptor gene mutation. Our study confirms the 10-15% prevalence of SRY mutations and shows the high prevalence (33%) of SF1 abnormalities in primary amenorrhea due to 46,XY DSD with low plasma testosterone concentration.ConclusionsThe genetic analysis of low-testosterone primary amenorrhea is complex as several factors may be involved. This work underlines the need to systematically analyze the SF1 sequence in girls with primary amenorrhea due to 46,XY DSD and low testosterone, as well as in newborns with 46,XY DSD.

Regulation of activities of steroid hormone receptors by tibolone and its primary metabolites

This work was undertaken (i) to study deeply the estrogen, androgen and progestative activities of tibolone and its metabolites (ii) to determine whether tibolone and its metabolites present glucocorticoid or mineralocorticoid activity. For this purpose, we used human cell lines bearing a luciferase gene with a responsive element under the control of human estrogen receptor alpha (ERalpha) or estrogen receptor beta (ERbeta) or androgen receptor (AR) or chimeric Gal4 fusion with progesterone receptor (PR), glucocorticoid receptor (GR) or mineralocorticoid receptor (MR). The major tibolone metabolites, the two hydroxymetabolites, bind and activate ER with a preference for ERalpha. Tibolone and the Delta(4)-tibolone are agonists for AR and PR and surprisingly 3alpha- and 3beta-OH-tibolone are antagonists for them. Moreover we showed for the first time that tibolone and its primary metabolites are GR and MR antagonists with a stronger affinity for MR than for GR. In conclusion, tibolone by these actions on different receptors and by this capacity to transform in different metabolites, has more complex effects than initially supposed.

Primary amenorrhea in four adolescents revealed 5α-reductase deficiency confirmed by molecular analysis

OBJECTIVE To determine the genetic cause of primary amenorrhea. DESIGN Case series. SETTING Pediatric endocrinology, endocrinology, and gynecology departments of academic hospitals. PATIENT(S) Three adolescents and one young woman 46, XY patients with srd5A2 gene mutations. MAIN OUTCOME MEASURE(S) Genetic analysis of srd5A2. RESULT(S) We report four srd5A2 gene mutations in three adolescents and one young woman with 46,XY primary amenorrhea. All presented clitoromegaly and two presented hypospadias; all had been reared as females. Virilization of the external genitalia was noted in the pubertal period in all four patients. Three were maintained in the female sex of rearing by personal choice, and the fourth switched gender. We identified the homozygous substitutions p.L55Q (exon 1), p.Q56R (exon 1), and p.N193S (exon 4), in patients 1, 2, and 3, respectively. Patient 4 had compound heterozygous mutations, a new c.34delG (exon 1) associated with p.R246W (exon 5). All patients had high plasma T levels (ranges, 16.2-23.2 nmol/L; normal female teenage range, 0.35-2 nmol/L). CONCLUSION(S) Our data clearly demonstrate that 5α-reductase deficiency should be considered in XY adolescents with primary amenorrhea and no breast development associated with virilization at puberty and high plasma T. Positive parental consanguinity should reinforce the diagnostic orientation.

Increased serum estrogenic bioactivity in girls with premature thelarche: a marker of environmental pollutant exposure?

Abstract The aim of the work was to investigate the pathophysiology of isolated premature thelarche (IPT) by determining the impact of pre/postnatal exposure to endocrine disrupting chemicals (EDCs) through evaluation of total serum estrogenic bioactivity (EBA). The pathophysiology remains elusive, although recent investigations suggested the role of EDCs in premature female breast development. We investigated 15 girls with IPT. Plasma estradiol, follicle-stimulating hormone, and luteinizing hormone were measured in basal state and after gonadotropin-releasing hormone testing; bone age and uterine length were also assessed for all patients. Total EBA of patient serum was analyzed with an ultrasensitive bioassay that we previously developed and compared with that of 18 age-matched control girls. Parents were interviewed about their environmental/occupational exposure to EDCs during the patient’s prenatal/postnatal life. Nine families reported parental occupational/environmental EDCs exposure during prenatal/postnatal patient life; the mean total EBA found in these 9 IPT girls was significantly elevated (12.31 ± 6.64 pg/mL) in comparison with that of the 6 patients without exposure (2.53 ± 0.73 pg/mL) and the 18 age-matched controls (3.53 ± 2.23 pg/mL; p < 0.01). The significant increase in total EBA in these 9 girls with IPT suggests that premature female breast development may be related in some cases to higher pre/postnatal contamination by EDCs.

Evidence of ERalpha and ERbeta selectivity and partial estrogen agonism in traditional Chinese medicine.

The use of complementary and alternative medicine and herbal products, especially traditional Chinese medicines, is progressively rising for both adults and children. This increased use is based on the popular belief that these medicines are safe and harmless. In this report, we describe the results of a bedside-to-bench study that involved a short-statured 4-year-old boy with deficiencies in growth hormone, thyroid stimulating hormone, and adrenocorticotropic hormone due to an ectopic posterior pituitary gland and invisible pituitary stalk. Although the boy was given replacement therapy with hydrocortisone and L-thyroxin, the parents refused to treat him with growth hormone and consulted a naturopath who prescribed a traditional Chinese medicine (TCM) to stimulate the boy’s growth. From the age of 20 months, the child’s growth was regularly monitored while he was being treated with hydrocortisone, thyroxin, and the TCM. Over a 36-month period, the child’s growth velocity accelerated (3 cm/year to 8 cm/year), his height increment substantially increased (-2 SD to -0.8 SD), and his bones matured. In the laboratory investigation, estrogen receptor (ER)alpha and ERbeta reporter cell lines were used to characterize the estrogenic activity of the TCM medicine and its 18 components, and the results established that the medicine and some of its components have estrogen receptor ERalpha and ERbeta selectivity and partial estrogen agonism. Partial estrogenic activity of the TCM was confirmed using whole-cell competitive binding, cell proliferation, and endogenous gene expression assays in the ERalpha-positive breast cancer cell lines. Although the presence of evidence is not always evidence of causality, we have concluded that this traditional Chinese medicine contains ingredients with estrogenic activity that can sustain bone growth and maturation without affecting other estrogen-dependent tissues.

Isolated Cushing's syndrome: an unusual presentation of McCune-Albright syndrome in the neonatal period.

Cushing’s syndrome (CS) may develop at any time in childhood. In the neonatal period, the major cause is the overactivation of adrenal cells within the context of McCune-Albright syndrome (MAS). The hypercorticism usually appears with other clinical signs of MAS. We report here a case of isolated neonatal CS as the initial evidence of MAS. This newborn girl was referred to our pediatric endocrine unit at the age of 3 months for hypotonia and growth retardation. Clinical examination revealed facial plethora, moon face, and swollen limbs. Laboratory data demonstrated ACTH-independent CS. Magnetic resonance imaging showed moderate bilateral adrenal hyperplasia, though more marked in the left adrenal gland, without nodules. This peripheral hypercorticism without well-defined adrenal tumor was suggestive of MAS, although no other signs like precocious puberty or café-au-lait spots were found. An activating Gsα gene mutation was found on DNA extracted from blood. Because MAS is a somatic disease, usually with unilateral effects, we tried to remove only the larger adrenal gland, where the mutation was demonstrated. This female newborn later developed the classical triad of MAS, reinforcing this diagnosis. Cushing’s syndrome in infants, even when isolated, may suggest a diagnosis of MAS.

Fetal ovarian cysts: an early manifestation of McCune–Albright syndrome?

Beyond the classic triad of peripheral precocious puberty, café‐au‐lait skin pigmentation and polyostotic fibrous dysplasia, partial presentation McCune–Albright syndrome (MAS) has been reported, including the association of isolated recurrent ovarian cysts in early infancy. The aims of this study were to determine whether isolated voluminous fetal unilateral ovarian cysts (diameter > 4 cm) may be associated with a Gsα activating mutation, suggestive of MAS.

A novel variant of DHH in a familial case of 46,XY Disorder of Sex Development: insights from Molecular Dynamics simulations

Disorders of sex development (DSD) are a heterogeneous group of conditions affecting the differentiation and development of the internal and external genitalia. Here, we aimed at identifying the genetic cause of DSD in two 46,XY sisters from a consanguineous family.

Functional and Structural Study of the Amino Acid Substitution in a Novel Familial Androgen Receptor Mutation (W752G) Responsible for Complete Androgen Insensitivity Syndrome

Mutations of the androgen receptor (AR) gene are the most frequent cause of 46,XY disorders of sex development. They are associated with a variety of phenotypes, ranging from phenotypic women (complete androgen insensitivity syndrome, CAIS) to milder degrees of undervirilization (partial forms) or men with only infertility (mild form). We identified a new W752G AR mutation responsible for a familial case of CAIS and performed an in vitro study and structural analysis of this mutation and the only other reported substitution affecting the same amino acid (W752R). Although sex assignment is not discussed in cases of CAIS, we show how the phenotype-genotype correlation can be refined by in vitro and structural studies according to the nature of the amino acid substitution, which in turn may have interesting impacts on the follow-up of these patients.