According to The Mayo Clinic , male hypogonadism can begin during fetal development, before puberty, or even during adulthood. In the case of adult hypogonadism, the condition can cause erectile dysfunction, infertility, decrease in beard and body hair growth, decrease in muscle mass, development of breast tissue, and loss of bone mass. The condition can also cause mental and emotional changes similar to those women may experience during menopause. These may include fatigue, decreased sex drive, difficulty concentrating, and hot flashes, The Mayo Clinic reported.
Caronia et al. (2011) studied 55 women with functional hypothalamic amenorrhea, who had all completed puberty spontaneously and had a history of secondary amenorrhea for 6 months or more, with low or normal gonadotropin levels and low serum estradiol levels. All had 1 or more predisposing factors, including excessive exercise, loss of more than 15% of body weight, and/or a subclinical eating disorder, and all had normal results on neuroimaging. The authors screened 7 HH-associated genes in the 55 affected women and identified 7 patients from 6 families who carried heterozygous mutations, including 1 in KAL1, 2 in FGFR1, 2 in PROKR2, and 1 in the GNRHR gene. Since these women with mutations resumed regular menses after discontinuing hormone-replacement therapy, Caronia et al. (2011) concluded that the genetic component of hypothalamic amenorrhea predisposes patients to, but is not sufficient to cause, GnRH deficiency.