scholarly journals Genetic Etiology of Idiopathic Hypogonadotropic Hypogonadism

Endocrines ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 1-15
Author(s):  
Ali Kemal Topaloglu ◽  
Ihsan Turan

Idiopathic hypogonadotropic hypogonadism (IHH) is a group of rare developmental disorders characterized by low gonadotropin levels in the face of low sex steroid hormone concentrations. IHH is practically divided into two major groups according to the olfactory function: normal sense of smell (normosmia) nIHH, and reduced sense of smell (hyposmia/anosmia) Kallmann syndrome (KS). Although mutations in more than 50 genes have been associated with IHH so far, only half of those cases were explained by gene mutations. Various combinations of deleterious variants in different genes as causes of IHH have been increasingly recognized (Oligogenic etiology). In addition to the complexity of inheritance patterns, the spontaneous or sex steroid-induced clinical recovery from IHH, which is seen in approximately 10–20% of cases, blurs further the phenotype/genotype relationship in IHH, and poses challenging steps in new IHH gene discovery. Beyond helping for clinical diagnostics, identification of the genetic mutations in the pathophysiology of IHH is hoped to shed light on the central governance of the hypothalamo-pituitary-gonadal axis through life stages. This review aims to summarize the genetic etiology of IHH and discuss the clinical and physiological ramifications of the gene mutations.

2012 ◽  
Vol 4 (3) ◽  
pp. 121-126 ◽  
Author(s):  
Fatih Gürbüz ◽  
L. Damla Kotan ◽  
Eda Mengen ◽  
Zeynep Şıklar ◽  
Merih Berberoğlu ◽  
...  

2021 ◽  
Vol 14 (4) ◽  
pp. e239495
Author(s):  
Grace Cham ◽  
Brooke O'Brien ◽  
Rebecca MN Kimble

Idiopathic hypogonadotropic hypogonadism (IHH) refers to a family of genetic disorders that affect the production and/or action of gonadotropic-releasing hormone, resulting in reduced serum levels of sex steroids. This condition has a prevalence of 1–10 cases/100 000 births and is characterised by the absence of spontaneous pubertal development. In women, the condition is characterised by the onset of normal adrenarche, with the absence of thelarche and menarche. Pubertal induction for breast development and uterine growth with oestradiol, and sequential maintenance of a normal menstrual cycle and adequate oestrogen for bone health, with an oestrogen and progesterone, is considered first-line treatment. Pregnancy can be achieved in patients who have received and responded to treatment with ovulation induction with exogenous gonadotrophins. Advances in genetic testing have led to increased research and understanding of the underlying genetics of IHH with gene mutations described in up to 50% of all IHH cases.


2019 ◽  
Vol 105 (5) ◽  
pp. 1515-1526
Author(s):  
Jia-Da Li ◽  
Jiayu Wu ◽  
Yaguang Zhao ◽  
Xinying Wang ◽  
Fang Jiang ◽  
...  

Abstract Purpose Idiopathic hypogonadotropic hypogonadism (IHH) and CHARGE (C, coloboma; H, heart abnormalities; A, choanal atresia, R, retardation of growth and/or development; G, gonadal defects; E, ear deformities and deafness) syndrome are 2 distinct developmental disorders sharing features of hypogonadism and/or impaired olfaction. CHD7 variants contribute to >60% CHARGE syndrome and ~10% IHH patients. A variety of extended CHARGE-like features are frequently reported in CHARGE patients harboring CHD7 variants. In this study, we aimed to systematically analyze the diagnostic CHARGE features and the extended CHARGE-like features in patients with IHH with CHD7 variants. Methods Rare sequencing variants (RSVs) in CHD7 were identified through exome sequencing in 177 IHH probands. Detailed phenotyping was performed in the IHH patients harboring CHD7 variants and their available family members. Results CHD7 RSVs were identified in 10.2% (18/177) of the IHH probands. Two diagnostic CHARGE features, hearing loss and ear deformities, were significantly enriched in patients with CHD7 variants. Furthermore, CHD7 variants were significantly associated with a panel of extended CHARGE-like phenotypes, including mild ocular defects, dyspepsia/gastroesophageal reflux disease and skeletal defects. We also developed a predictive model for prioritizing CHD7 genetic testing in IHH patients. Conclusion CHD7 variants rarely cause isolated IHH. Surveillance of symptoms in CHARGE syndrome-affected organs will facilitate the proper treatment for these patients. Certain clinical features can be useful for prioritizing CHD7 genetic screening.


2018 ◽  
Vol 2 (11) ◽  
pp. 1293-1305
Author(s):  
Margaret F Lippincott ◽  
Kiana Nguyen ◽  
Angela Delaney ◽  
Yee-Ming Chan ◽  
Stephanie Beth Seminara

2004 ◽  
Vol 11 (4) ◽  
pp. 725-748 ◽  
Author(s):  
G S Harrison ◽  
M E Wierman ◽  
T M Nett ◽  
L M Glode

Gonadotropin-releasing hormone (GnRH) is the hypothalamic factor that mediates reproductive competence. Intermittent GnRH secretion from the hypothalamus acts upon its receptor in the anterior pituitary to regulate the production and release of the gonadotropins, LH and FSH. LH and FSH then stimulate sex steroid hormone synthesis and gametogenesis in the gonads to ensure reproductive competence. The pituitary requires pulsatile stimulation by GnRH to synthesize and release the gonadotropins LH and FSH. Clinically, native GnRH is used in a pump delivery system to create an episodic delivery pattern to restore hormonal defects in patients with hypogonadotropic hypogonadism. Agonists of GnRH are delivered in a continuous mode to turn off reproductive function by inhibiting gonadotropin production, thus lowering sex steroid production, resulting in medical castration. They have been used in endocrine disorders such as precocious puberty, endometriosis and leiomyomata, but are also studied extensively in hormone-dependent malignancies. The detection of GnRH and its receptor in other tissues, including the breast, ovary, endometrium, placenta and prostate suggested that GnRH agonists and antagonists may also have direct actions at peripheral targets. This paper reviews the current data concerning differential control of GnRH and GnRH receptor expression and signaling in the hypothalamic–pituitary axis and extrapituitary tissues. Using these data as a backdrop, we then review the literature about the action of GnRH in cancer cells, the utility of GnRH analogs in various malignancies and then update the research in novel therapies targeted to the GnRH receptor in cancer cells to promote anti-proliferative effects and control of tumor burden.


2013 ◽  
Author(s):  
Yui Watanabe ◽  
Takeshi Hayashi ◽  
Hiroyuki Yamazaki ◽  
Katsuyoshi Tojo ◽  
Kazunori Utsunomiya

2015 ◽  
Author(s):  
Sasha Howard ◽  
Ariel Poliandri ◽  
Helen Storr ◽  
Louise Metherell ◽  
Claudia Cabrera ◽  
...  

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