Absent or decreased gonadal function (the male testis or the female ovary) resulting from the absence of the gonadal stimulating pituitary hormones FSH ( follicle stimulating hormone ) and LH ( luteinizing hormone ).
Alternative Names
Gonadotropin deficiency; Kallmann syndrome; Hypogonadotropic hypogonadism and anosmia; Hypogonadism with anosmia; Secondary hypogonadism
Causes, incidence, and risk factors
One area of the brain, the hypothalmus, secretes hormones (GnRH) to stimulate the pituitary gland. In response, the pituitary gland (located near the brain) secretes other hormones ( FSH and LH ). These, in turn, stimulate the ovaries (female) and testes (male) to secrete hormones that are responsible for normal sexual development in puberty. Any disruption in this cascade causes a deficiency of the sex hormones and halts normal pubertal sexual maturation. Failure of the hypothalamus is most commonly a result of Kallmann syndrome. Kallmann syndrome is an inherited disorder that usually includes a disorder of the sense of smell. Failure of the pituitary may result from empty sella syndrome , pituitary tumors ( craniopharyngioma ), head injuries , or other causes.
Expectations (prognosis)
With proper hormonal stimulation, puberty can be induced and fertility may be restored.
Calling your health care provider
Call your health care provider if your child does not enter puberty as expected.
Prevention
Prevention is dependent on the cause. Genetic counseling may be appropriate for individuals with heritable disorders that are associated with hypogonadism. Prevention of serious head injuries reduces the risk of pituitary injury associated hypogonadotropic hypogonadism.