Hypogonadotropic hypogonadism

Hypogonadotropic hypogonadism is a genetically heterogeneous disorder characterized by infertility and... 

Hypogonadotropic hypogonadism Gonadotropin-releasing hormone (GnRH) receptor GnRH peptidomimetic antagonist... 

Chorionic gonadotropin (HCG) is extracted from human placentas. The actions of HCG are identical to those of the pituitary LH. The hormone is used to induce ovulation in anovulatory women. This drug is also used for the treatment of prepubertal cryptorchism (failure of the testes to descend into the scrotum) and in men to treat selected cases of hypogonadotropic hypogonadism. 

Quinton H.W., Grant W., Thrasivoulou C.Q. and Besser G.M. (1997). Gonadotropin-releasing hormone immunoreactivity in the nasal epithelia of adults with Kallmann s syndrome and isolated hypogonadotropic hypogonadism, in the early midtrimester human fetus. J Clin Endocrinol Metab 82, 309-314. 

Gonadotropin-Releasing Hormone Receptor Mutations and Idiopathic Hypogonadotropic Hypogonadism... 

Seminara, S. B., Hayes, F. J., and Crowley, W. F. (1998) Gonadotropin-releasing hormone deficiency in the human (Idiopathic hypogonadotropic hypogonadism and Kallmann s syndrome) Pathophysiological and genetic considerations. Endocr. Rev. 19, 521-539. 

Habiby, R. L., Boepple, P., NachtigaU, L., Sluss, P. M., Crowley, W. F., and Jameson, J. L. (1996) Adrenal hypoplasia congenita with hypogonadotropic hypogonadism—evidence that DAX-1 mutations lead to combined hypothalamic and pituitary defects in gonadotropin production. J. Clin. Invest. 98, 1055-1062. 

Beranova, M., Oliveira, L. M. B., Bedecarrats, G. Y., et al. (2001) Prevalence, phenotypic spectrum, and modes of inheritance of gonadotropin-releasing hormone receptor mutations in idiopathic hypogonadotropic hypogonadism. J. Clin. Endocrinol. Metab. 86,1580-1588. 

Layman, L. C., Cohen, D. P., Jin, M., et al. (1998) Mutations in gonadotropin-releasing hormone receptor gene cause hypogonadotropic hypogonadism. Nat. Genet. 18, 14-15. 

Hypogonadotropic hypogonadism (congenital or acquired) Idiopathic gonadotropin or luteinizing hormone releasing hormone (LHRH) deficiency or pituitary-hypothalamic injury from tumors, trauma, or radiation. 

Gonadotropins are used to induce spermatogenesis in hypogonadotropic hypogonadal men a lengthy treatment is required to obtain mature sperm. For several weeks hCG is injected to increase testosterone levels, followed by injections of menotropins for several months. Prepubertal cryptorchidism can be treated by injections of hCG for up to several months. 

G. Other considerations Recombinant follitropin alfa has been designated an orphan product for the induction of spermatogenesis in men with primary and secondary hypogonadotropic hypogonadism in whom the cause of infertility is not due to primary testicular failure. 

JarowJP, Lipshultz LI. Anabolic steroid-induced hypogonadotropic hypogonadism. Am J Sports Med. 1990 18 429-431. 

Delayed puberty in a hypogonadotropic adolescent may be due to a constitutional delay or to hypogonadotropic hypogonadism. The LH response (but not the FSH response) to GnRH can distinguish between these two conditions. Serum LH levels are measured before and then 15, 30,... 

GnRH can stimulate pituitary function and is used to treat infertility caused by hypothalamic hypogonadotropic hypogonadism in both sexes. A portable battery-powered programmable pump and intravenous tubing allows pulsatile GnRH therapy every 90 minutes. 

Over 50% of men with hypogonadotropic hypogonadism become fertile after hMG or hCG/FSH administration. 

Patients with constitutional delay in onset of puberty can be distinguished from those with hypogonadotropic hypogonadism using repeated hCG stimulation. Serum testosterone and estradiol levels rise in the former but not in the latter group. 

Pitteloud, N., Zhang, C., Pignatelli, D., Li, J. D., Raivio, T., Cole, L. W., Plummer, L., Jacobson-Dickman, E. E., Mellon, P. L., Zhou, Q. Y., and Crowley, W. F. Jr. (2007). Loss-of-function mutation in the prokinetidn 2 gene causes Kallmann syndrome and normosmic idiopathic hypogonadotropic hypogonadism. Proc. Natl. Acad. Sci. USA 104, 17447-17452. 

There are a number of abnormalities that can affect the male reproductive system before birth, in childhood, or in adulthood. For the purposes of this chapter, they have been divided into categories of (1) hypogonadotropic hypogonadism, (2) hypergonadotropic hypogonadism, (3) defects in androgen action (Box 53-1), (4) impotence, and (5) gynecomastia. The effects of these abnormalities on infertility are discussed later in this chapter. 

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