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Taneli Raivio - One of the best experts on this subject based on the ideXlab platform.

  • Constitutional delay of puberty versus congenital Hypogonadotropic Hypogonadism: Genetics, management and updates.
    Best practice & research. Clinical endocrinology & metabolism, 2019
    Co-Authors: Taneli Raivio, Päivi J. Miettinen
    Abstract:

    Delayed puberty (DP) affects approximately 2% of adolescents. In the vast majority of patients in both sexes, it is due to constitutional delay of growth and puberty (CDGP), a self-limited condition in which puberty starts later than usual but progresses normally. However, some CDGP patients may benefit from medical intervention with low-dose sex steroids or peroral aromatase inhibitor letrozole (only for boys). Other causes of DP include permanent Hypogonadotropic Hypogonadism, functional Hypogonadotropic Hypogonadism (due to chronic diseases and conditions), and gonadal failure. In this review we discuss these themes along with the latest achievements in the field of puberty research, and include a brief synopsis on the differential diagnosis and management of patients with CDGP and congenital Hypogonadotropic Hypogonadism.

  • Mutation screening of SEMA3A and SEMA7A in patients with congenital Hypogonadotropic Hypogonadism.
    Pediatric research, 2014
    Co-Authors: Johanna Känsäkoski, Taneli Raivio, Nelly Pitteloud, Eeva-maria Laitinen, Kirsi Vaaralahti, Rainer Fagerholm, Peter Hackman, Johanna Tommiska
    Abstract:

    Mutation screening of SEMA3A and SEMA7A in patients with congenital Hypogonadotropic Hypogonadism

  • Reversible Congenital Hypogonadotropic Hypogonadism in Patients with CHD7, FGFR1 or GNRHR Mutations
    PloS one, 2012
    Co-Authors: Eeva-maria Laitinen, Johanna Tommiska, Timo Sane, Kirsi Vaaralahti, Jorma Toppari, Taneli Raivio
    Abstract:

    Background Congenital Hypogonadotropic Hypogonadism (HH) is a rare cause for delayed or absent puberty. These patients may recover from HH spontaneously in adulthood. To date, it is not possible to predict who will undergo HH reversal later in life. Herein we investigated whether Finnish patients with reversal of congenital Hypogonadotropic Hypogonadism (HH) have common phenotypic or genotypic features.

  • Reversal of Idiopathic Hypogonadotropic Hypogonadism
    The New England journal of medicine, 2007
    Co-Authors: Taneli Raivio, John L. Falardeau, Andrew A. Dwyer, Richard Quinton, Frances J. Hayes, Virginia A. Hughes, Lindsay W. Cole, Simon H. S. Pearce, Hang Lee, Paul A. Boepple
    Abstract:

    Background Idiopathic Hypogonadotropic Hypogonadism, which may be associated with anosmia (the Kallmann syndrome) or with a normal sense of smell, is a treatable form of male infertility caused by a congenital defect in the secretion or action of gonadotropin-releasing hormone (GnRH). Patients have absent or incomplete sexual maturation by the age of 18. Idiopathic Hypogonadotropic Hypogonadism was previously thought to require lifelong therapy. We describe 15 men in whom reversal of idiopathic Hypogonadotropic Hypogonadism was sustained after discontinuation of hormonal therapy. Methods We defined the sustained reversal of idiopathic Hypogonadotropic Hypogonadism as the presence of normal adult testosterone levels after hormonal therapy was discontinued. Results Ten sustained reversals were identified retrospectively. Five sustained reversals were identified prospectively among 50 men with idiopathic Hypogonadotropic Hypogonadism after a mean (±SD) duration of treatment interruption of 6±3 weeks. Of the ...

Ursula B. Kaiser - One of the best experts on this subject based on the ideXlab platform.

  • The genetic and molecular basis of idiopathic Hypogonadotropic Hypogonadism
    Nature Reviews Endocrinology, 2009
    Co-Authors: Suzy D.c. Bianco, Ursula B. Kaiser
    Abstract:

    The genetic basis of the vast majority of cases of idiopathic Hypogonadotropic Hypogonadism (IHH) remains unknown IHH with anosmia (Kallmann syndrome) is caused by the defective developmental migration of gonadotropin-releasing hormone (GnRH) and olfactory neurons; associated genes encode proteins involved in this migration Molecular mechanisms that underlie IHH in patients with a normal sense of smell are diverse and may involve genes that regulate development and/or GnRH secretion or action A considerable number of IHH cases probably involve mutations in more than one gene; that is, these cases are polygenic Sex-associated factors also contribute to the IHH phenotype Idiopathic Hypogonadotropic Hypogonadism (IHH) has an incidence of 1–10 cases per 100,000 births. About 60% of patients with IHH present with associated anosmia, also known as Kallmann syndrome, characterized by total or partial loss of olfaction. Many of the gene mutations associated with Kallmann syndrome have been mapped to KAL1 or FGFR1 . However, together, these mutations account for only about 15% of Kallmann syndrome cases. More recently, mutations in PROK2 and PROKR2 have been linked to the syndrome and may account for an additional 5–10% of cases. The remaining 40% of patients with IHH have a normal sense of smell. Prior to 2003, the only gene linked to normosmic IHH was the gonadotropin-releasing hormone receptor gene. However, mutations in this receptor are believed to account for only 10% of cases. Subsequently, mutations in KISS1R , TAC3 and TACR3 were identified as causes of normosmic IHH. Certain genes, including PROK2 and FGFR1 , are associated with both anosmic and normosmic IHH. Despite recent advances in the field, the genetic causes of the majority of cases of IHH remain unknown. This Review discusses genes associated with Hypogonadotropic disorders and the molecular mechanisms by which mutations in these genes may result in IHH. Mutations in a number of genes have been identified in patients as the primary genetic cause of idiopathic Hypogonadotropic Hypogonadism. These genes encode proteins that regulate gonadotropin-releasing hormone (GnRH) neuron development, migration from the nasal placode to the hypothalamus, GnRH secretion or GnRH action. This Review discusses genes associated with Hypogonadotropic disorders and the molecular mechanisms by which mutations in these genes may result in idiopathic Hypogonadotropic Hypogonadism.

  • The genetic and molecular basis of idiopathic Hypogonadotropic Hypogonadism.
    Nature reviews. Endocrinology, 2009
    Co-Authors: Suzy D.c. Bianco, Ursula B. Kaiser
    Abstract:

    Mutations in a number of genes have been identified in patients as the primary genetic cause of idiopathic Hypogonadotropic Hypogonadism. These genes encode proteins that regulate gonadotropin-releasing hormone (GnRH) neuron development, migration from the nasal placode to the hypothalamus, GnRH secretion or GnRH action. This Review discusses genes associated with Hypogonadotropic disorders and the molecular mechanisms by which mutations in these genes may result in idiopathic Hypogonadotropic Hypogonadism.

Johanna Tommiska - One of the best experts on this subject based on the ideXlab platform.

Päivi J. Miettinen - One of the best experts on this subject based on the ideXlab platform.

  • Constitutional delay of puberty versus congenital Hypogonadotropic Hypogonadism: Genetics, management and updates.
    Best practice & research. Clinical endocrinology & metabolism, 2019
    Co-Authors: Taneli Raivio, Päivi J. Miettinen
    Abstract:

    Delayed puberty (DP) affects approximately 2% of adolescents. In the vast majority of patients in both sexes, it is due to constitutional delay of growth and puberty (CDGP), a self-limited condition in which puberty starts later than usual but progresses normally. However, some CDGP patients may benefit from medical intervention with low-dose sex steroids or peroral aromatase inhibitor letrozole (only for boys). Other causes of DP include permanent Hypogonadotropic Hypogonadism, functional Hypogonadotropic Hypogonadism (due to chronic diseases and conditions), and gonadal failure. In this review we discuss these themes along with the latest achievements in the field of puberty research, and include a brief synopsis on the differential diagnosis and management of patients with CDGP and congenital Hypogonadotropic Hypogonadism.

Jacques Young - One of the best experts on this subject based on the ideXlab platform.

  • Approach to the Male Patient with Congenital Hypogonadotropic Hypogonadism
    The Journal of clinical endocrinology and metabolism, 2012
    Co-Authors: Jacques Young
    Abstract:

    The term "congenital Hypogonadotropic Hypogonadism" (CHH) refers to a group of disorders featuring complete or partial pubertal failure due to insufficient secretion of the pituitary gonadotropins LH and FSH. Many boys (or their parents) will seek medical consultation because of partial or absent virilization after 14 yr of age. Small testes are very frequent, but height is generally normal. Laboratory diagnosis of Hypogonadotropic Hypogonadism is relatively simple, with very low circulating total testosterone and low to low-normal gonadotropin and inhibin B levels. This hormone profile rules out a primary testicular disorder. Before diagnosing CHH, however, it is necessary to rule out a pituitary tumor or pituitary infiltration by imaging studies, juvenile hemochromatosis, and a systemic disorder that, by undermining nutritional status, could affect gonadotropin secretion and pubertal development. Anterior pituitary function must be thoroughly investigated to rule out a more complex endocrine disorder with multiple hormone deficiencies and thus to conclude that the Hypogonadotropic Hypogonadism is isolated. The most likely differential diagnosis before age 18 yr is constitutional delay of puberty. Apart from non-Kallmann syndromic forms, which are often diagnosed during childhood, the two main forms of CHH seen by endocrinologists are Kallmann syndrome, in which CHH is associated with impaired sense of smell, and isolated CHH with normal olfaction. Anosmia can be easily diagnosed by questioning the patient, whereas olfactometry is necessary to determine reliably whether olfaction is normal or partially defective. This step is important before embarking on a search for genetic mutations, which will also be useful for genetic counseling. The choice of a particular hormone replacement therapy protocol aimed at virilizing the patient will depend on age at diagnosis and local practices.

  • Loss of function mutations of the GnRH receptor: a new cause of Hypogonadotropic Hypogonadism.
    Journal of Pediatric Endocrinology and Metabolism, 1999
    Co-Authors: N. De Roux, Jacques Young, Micheline Misrahi, G. Schaison, Edwin Milgrom
    Abstract:

    : The association of Hypogonadotropic Hypogonadism with anosmia defines Kallmann's syndrome. The gene of the X-linked form of this syndrome has been cloned and several mutations described. However, the relatively small number of Hypogonadotropic hypogonadic patients with Kallmann's gene defects supports the hypothesis that other genes may be involved. Idiopathic Hypogonadotropic Hypogonadism (IHH) is not associated with anosmia. The GnRH gene was excluded as a candidate gene in IHH since no abnormality was found in several patients. The action of the GnRH is mediated through a G-protein coupled receptor present in the cell membrane of gonadotropes. The GnRH receptor was thus another candidate gene. Recently, we described the first patient with partial Hypogonadotropic Hypogonadism without anosmia caused by loss of function mutations of the GnRH receptor. We compare this first family with a new family presenting complete Hypogonadotropic Hypogonadism and a variable degree of gonadotrope deficiency in the affected kindred, and discuss genotype-phenotype correlation.

  • A Family with Hypogonadotropic Hypogonadism and Mutations in the Gonadotropin-Releasing Hormone Receptor
    The New England journal of medicine, 1997
    Co-Authors: N. De Roux, Jacques Young, Micheline Misrahi, R. Genet, Philippe Chanson, G. Schaison, Edwin Milgrom
    Abstract:

    Hypogonadotropic Hypogonadism is often associated with anosmia in a condition known as Kallmann's syndrome. The gene for the X-linked form of Kallmann's syndrome has been mapped to chromosome Xp22.3,1 and several mutations have been described.2–4 In idiopathic Hypogonadotropic Hypogonadism there is no anosmia, and the involved genes have not been characterized. One possible candidate is the gene for gonadotropin-releasing hormone (GnRH), especially since hypogonadal mice with the deletion of this gene have been identified.5 However, no abnormality of the gene for GnRH has been found in several patients with idiopathic Hypogonadotropic Hypogonadism.6–9 The gene for the GnRH receptor . . .