41 research outputs found

    What Does AMH Tell Us in Pediatric Disorders of Sex Development?

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    Disorders of sex development (DSD) are conditions where genetic, gonadal and/or internal/external genital sex are discordant. In many cases, serum testosterone determination is insufficient for the differential diagnosis. Anti-Müllerian hormone (AMH), a glycoprotein hormone produced in large amounts by immature testicular Sertoli cells, may be an extremely helpful parameter. In undervirilized 46,XY DSD, AMH is low in gonadal dysgenesis while it is normal or high in androgen insensitivity and androgen synthesis defects. Virilization of a 46,XX newborn indicates androgen action during fetal development, either from testicular tissue or from the adrenals or placenta. Recognizing congenital adrenal hyperplasia is usually quite easy, but other conditions may be more difficult to identify. In 46,XX newborns, serum AMH measurement can easily detect the existence of testicular tissue, leading to the diagnosis of ovotesticular DSD. In sex chromosomal DSD, where the gonads are more or less dysgenetic, AMH levels are indicative of the amount of functioning testicular tissue. Finally, in boys with a persistent Müllerian duct syndrome, undetectable or very low serum AMH suggests a mutation of the AMH gene, whereas normal AMH levels orient towards a mutation of the AMH receptor.Fil: Josso, Nathalie. Inserm; FranciaFil: Rey, Rodolfo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones Endocrinológicas "Dr. César Bergada". Gobierno de la Ciudad de Buenos Aires. Centro de Investigaciones Endocrinológicas "Dr. César Bergada". Fundación de Endocrinología Infantil. Centro de Investigaciones Endocrinológicas "Dr. César Bergada"; Argentin

    Anti-Müllerian hormone : a look back and ahead

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    International audienceAMH is a member of the TGF-β family secreted by immature Sertoli cells and by the granulosa cells of growing ovarian follicles. In males, it induces the regression of fetal Müllerian ducts and represses androgen synthesis through receptors located on the Leydig cell membrane. In female mice, AMH inhibits primary follicle recruitment and sensitivity to FSH. Measurement of circulating AMH is of value to pediatric endocrinologists allowing them to detect the presence and functional activity of testicular tissue without resorting to stimulation by human chorionic gonadotropin. In women, AMH levels are correlated with the size of the ovarian follicle pool and provide information on the likehood of spontaneous or induced pregnancy

    Identification des voies de signalisation de l'hormone anti-Müllerienne

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    LE KREMLIN-B.- PARIS 11-BU Méd (940432101) / SudocPARIS-BIUM (751062103) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF

    Diagnosis and treatment of disorders of sexual development

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    -Wolffian ducts, the urogenital sinus and external genitalia virilize in proportion to androgen activity (androgen levels and androgen receptor expression in target organs) during the first trimester of fetal life. Müllerian duct regression is commensurate with AMH activity (AMH produced by the gonads and AMH receptor expression in Müllerian ducts) during the first 10 weeks of fetal life. -Defects in gonadal differentiation lead to Dysgenetic DSD, consisting of lack of virilization and persistence of Müllerian derivatives in patients with a Y chromosome. There is an increased risk of gonadal tumor development. -Defects in androgen production or action lead to a form of hormone-dependent DSD, consisting of lack of virilization, without persistence of Müllerian derivatives in patients with a Y chromosome. -Defects in AMH production or action lead to the Persistent Müllerian Duct Syndrome, characterized by the persistence of Müllerian remnants in an otherwise normally virilized newborn. -Excessive levels of androgens result in virilization of XX fetuses. -Management of patients with DSD requires a holistic, multi-disciplinary approach: evaluation and long-term management must be performed at a center with an experienced multidisciplinary team. -Gender assignment in newborns should be delayed until expert evaluation has taken place; all individuals should receive a gender assignment following open communication with parents whose participation in decision making is encouraged. Patient and family concerns should be respected and addressed in strict confidence.Fil: Rey, Rodolfo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones Endocrinológicas "Dr. César Bergada". Gobierno de la Ciudad de Buenos Aires. Centro de Investigaciones Endocrinológicas "Dr. César Bergada". Fundación de Endocrinología Infantil. Centro de Investigaciones Endocrinológicas "Dr. César Bergada"; ArgentinaFil: Josso, Nathalie. No especifíca

    AMH and AMH receptor defects in persistent Müllerian duct syndrome.

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    International audienceAnti-Müllerian hormone (AMH) produced by fetal Sertoli cells is responsible for regression of Müllerian ducts, the anlage for uterus and Fallopian tubes, during male sex differentiation. A member of the transforming growth factor-beta superfamily, AMH signals through two transmembrane receptors, type II which is specific and type I receptors, shared with the bone morphogenetic protein family. Mutations of the AMH and AMH receptor type II (AMHR-II) genes lead to persistence of the uterus and Fallopian tubes in males. Both conditions are transmitted according to a recessive autosomal pattern and are symptomatic only in males. Affected individuals are otherwise normally virilized, undergo normal male puberty; and may be fertile if testes, tightly attached to the Fallopian tubes, can be replaced in the scrotum. Approximately 85% of the cases are due, in similar proportions, to mutations of the AMH or AMHR-II gene. The genetic background does not influence the phenotype, the only difference is the level of circulating AMH which is normal for age in AMHR-II mutants and usually low or undetectable in AMH gene defects. This is due to lack of secretion, explained by the localization of the mutations in critical regions, based on the assumed 3D structure of the molecule. Similarly, lack of translocation to the surface membrane is responsible for the inactivity of AMHR-II molecules bearing mutations in the extracellular domain. In 15% of cases, the cause of the persistent Mullerian duct syndrome is unknown and could be related to complex malformations of the urogenital region, unrelated to AMH physiology

    L'hormone anti-müllérienne

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    International audienc

    Persistence of Müllerian derivatives in males.

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    International audienceThe persistent müllerian duct syndrome is a rare, autosomal recessive disorder, characterized by the persistence of müllerian duct derivatives-uterus and fallopian tubes-in genetic males otherwise normally virilized. We have collected DNA from 69 families with this syndrome. In 45%, a mutation of the anti-müllerian hormone (AMH) gene was detected; 52% were homozygous. The level of circulating AMH was extremely low in the great majority of patients, even before puberty, when AMH levels are normally high. Single-strand conformation polymorphism (SSCP)-polymerase chain reaction (PCR) was a very effective screening method. In 39% of families, characterized by an AMH level normal for the age of the patient, a mutation of the type II receptor of AMH was detected by automatic sequencing, because SSCP-PCR was not very effective. Forty-eight percent of the mutations were homozygous. A 27-base-pair deletion in exon 10 was noted in 45% of the families. When this very common mutation is not taken into account, the proportion of recurrent mutations is 42% for the AMH gene and 33% for the AMH receptor type II gene. In 16% of families, no mutation of either the AMH or the AMH receptor gene was detectable; this group may correspond to mutations of unknown genes involved in AMH processing or in downstream AMH transduction

    Testicular anti-müllerian hormone: Clinical applications in DSD

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    Male fetal sexual differentiation of the genitalia is driven by Leydig cell-secreted androgens and Sertoli cell-secreted anti-Müllerian hormone (AMH). Disorders of sex development (DSD) may be due to abnormal morphogenesis of genital primordia or to defective testicular hormone secretion or action. In dysgenetic DSD, due to an early fetal-onset primary hypogonadism affecting Leydig and Sertoli cells, the fetal gonads are incapable of producing normal levels of androgens and AMH. In non-dysgenetic DSD, either Leydig cells or Sertoli cells are affected but not both. Persistent Müllerian duct syndrome (PMDS) may result from Sertoli cell-specific dysfunction due to mutations in the AMH gene; these patients have Fallopian tubes and uterus, but male external genitalia. In DSD due to insensitivity to testicular hormones, fetal Leydig and Sertoli cell function is normal. Defective androgen action is associated with female or ambiguous genitalia whereas insensitivity to AMH results in PMDS with normal serum AMH. Clinical and biological features of PMDS due to mutations in the genes coding for AMH or the AMH receptor, as well as genetic aspects and clinical management are discussed. © 2012 by Thieme MedicalPublishers, Inc., 333 Seventh Avenue,New York, NY 10001, USA.Fil: Josso, Nathalie. Inserm; FranciaFil: Rey, Rodolfo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones Endocrinológicas "Dr. César Bergada". Gobierno de la Ciudad de Buenos Aires. Centro de Investigaciones Endocrinológicas "Dr. César Bergada". Fundación de Endocrinología Infantil. Centro de Investigaciones Endocrinológicas "Dr. César Bergada"; Argentina. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Picard, Jean-Yves. Inserm; Franci

    Anti-Müllerian Hormone: A Valuable Addition to the Toolbox of the Pediatric Endocrinologist

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    Anti-Müllerian hormone (AMH), secreted by immature Sertoli cells, provokes the regression of male fetal Müllerian ducts. FSH stimulates AMH production; during puberty, AMH is downregulated by intratesticular testosterone and meiotic germ cells. In boys, AMH determination is useful in the clinical setting. Serum AMH, which is low in infants with congenital central hypogonadism, increases with FSH treatment. AMH is also low in patients with primary hypogonadism, for instance in Down syndrome, from early postnatal life and in Klinefelter syndrome from mid-puberty. In boys with nonpalpable gonads, AMH determination, without the need for a stimulation test, is useful to distinguish between bilaterally abdominal gonads and anorchism. In patients with disorders of sex development (DSD), serum AMH determination helps as a first line test to orientate the etiologic diagnosis: low AMH is indicative of dysgenetic DSD whereas normal AMH is suggestive of androgen synthesis or action defects. Finally, in patients with Persistent Müllerian duct syndrome (PMDS), undetectable serum AMH drives the genetic search to mutations in the AMH gene, whereas normal or high AMH is indicative of an end organ defect due to AMH receptor gene defects.Fil: Josso, Nathalie. Universidad de París Sur, Francia;Fil: Rey, Rodolfo Alberto. Consejo Nacional de Invest.cientif.y Tecnicas. Oficina de Coordinacion Administrativa Pque. Centenario. Centro de Investigaciones Endocrinologicas; Universidad de Buenos Aires. Facultad de Medicina. Departamento de Biologia Celular E Histologia. Cat.de Histologia,citologia y Embriologia I; Argentina;Fil: Picard, Jean Yves. Universidad de París Sur, Francia
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