Hypogonadotropic hypogonadism
Alternative names:
gonadotropin deficiency; Kallmann syndrome; hypogonadotropic
hypogonadism and anosmia, hypogonadism with anosmia; secondary
hypogonadism
Definition:
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).
Causes, incidence, and risk factors:
FSH and LH
are hormones released by the pituitary gland. These hormones
stimulate the ovaries (female) and testes
(male) to secrete hormones that are responsible for normal
development in puberty. Decreased levels of FSH and LH may
occur in association with damage to or absence of the pituitary
(hypopituitarism) gland or hypothalamus.
In the absence of gonadal stimulation by FSH and LH puberty
does not take place and the secondary sexual characteristics
do not develop.
Deficient FSH and LH may also occur as a result of hypothalamic
abnormalities. The hypothalamus produces the gonadotropin-releasing
hormone (GnRH), which stimulates the pituitary to release
FSH and LH. If gonadotrophin-releasing hormone is absent,
the pituitary does not release FSH and LH and puberty does
not take place.
Failure of the pituitary may result from empty
sella syndrome, pituitary
tumors (craniopharyngioma),
head injuries, thalassemia
major, or other causes. Kallmann's syndrome is a hereditary
absence of the anterior
pituitary and the inability to smell (anosmia).
It is transmitted by eiher x-linked recessive (most common
form) or autosomal dominant (least common form) inheritance.
Kallmann syndrome is one of the more common causes of hypogonadotropic
hypogonadism.
The following is a list of other conditions that may be associated
with hypogonadotrophic hypogonadism:
- Heritable and genetic disorders
- Kallmann syndrome
- Laurence-Moon-Biedl syndrome
- Prader-Willi syndrome
- Marinesco-Sjogren syndrome
- Infectious diseases
- tuberculosis
- HIV infection and AIDS
- Collagen vascular disease
Updated Date: 02/09/00
Updated By:J. Gordon Lambert, MD, Associate Medical Director,
Utah Health Informatics and adam.com
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