Hypogonadotropic hypogonadism is a form of hypogonadism that is due to a problem with the pituitary gland or hypothalamus. In this condition, the male testes or the female ovaries produce little or no hormones.
Gonadotropin deficiency; Secondary hypogonadism; Kallmann syndrome
Causes, incidence, and risk factors
Hypogonadotropic hypogonadism is caused by a lack of secretion of the gonadal stimulating pituitary hormones: follicle stimulating hormone (FSH) and luteinizing hormone (LH).
Normally, the hypothalamus in the brain releases gonadotropin-releasing hormone (GnRH). This hormone stimulates the pituitary gland to release other hormones, including FSH and LH. These hormones tell the female ovaries and male testes to release hormones that lead to normal sexual development in puberty. Any change in this hormone release chain causes a lack of sex hormones and prevents normal sexual maturity.
Failure of the hypothalamus is usually a result of Kallmann syndrome. Kallmann syndrome is an inherited form of hypogonadotropic hypogonadism that can occur with a loss of smell.
- In females, absence of breasts and menstruation
- In males, enlargement of the testes and penis, deepening of the voice, and facial hair
- Inability to smell (in some cases)
- Lack of development at puberty (development may be incomplete or significantly delayed)
- Short stature (in some cases)
Signs and tests
Tests that may be done include:
- Blood tests to measure hormone levels
- LH response to GnRH
- MRI of the head (to look for a noncancerous growth in the pituitary gland)
- Genetic testing
Treatment depends on the source of the problem, but may involve:
- Injections of testosterone
- Slow-release testosterone skin patch
- Testosterone gels
- Estrogen and progesterone pills
- GnRH injections
With the right hormone treatment, the person can go through puberty, and fertility may be restored.
- Delayed puberty
- Low self-esteem due to late start of puberty (emotional support may be helpful)
Calling your health care provider
Call your health care provider if your child does not enter puberty as expected.
Prevention depends on the cause.
People who have a family history of inherited conditions that cause hypogonadism may benefit from genetic counseling. Preventing serious head injuries reduces the risk of hypogonadotropic hypogonadism due to pituitary injury.
Styne DM, Grumbach MM. Puberty: Ontogeny, neuroendocrinology, physiology, and disorders. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology. 12th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 25.