21. Lack of GnRH ultimately leads to hypogonadism . 22. Both female and male mice homozygous for a FANCA mutation show hypogonadism and impaired fertility. 23. Men with hypogonadism have extremely low levels of testosterone due to decreased function of the testes. 24. Hypogonadism is also categorized by endocrinologists by the level of the reproductive system that is defective.25. Women with hypogonadism do not begin menstruating and it may affect their height and breast development. 26. For example, the male mutation of the GnRH coding gene could result in hypogonadotrophic hypogonadism . 27. Clomifene is sometimes used in the treatment of male hypogonadism as an alternative to testosterone replacement therapy. 28. A 2007 paper proposed a possible digenic model for Kallmann syndrome and other forms of hypogonadotrophic hypogonadism . 29. Humans with a FANCD deficiency display hypogonadism , male infertility, impaired spermatogenesis, and reduced female fertility. 30. The cause of low testosterone is usually a rare condition called hypogonadism , in which the testicles are underactive.
