Saturday, May 30, 2015 | 12:07 AM

Madisons Foundation - Moms And Dads In Search Of Needed Support

Kallmann's Syndrome
Thursday, 19 August 2004
Thursday, 19 August 2004
Hypogonadotropic Hypogonadism


Kallmann’s syndrome is a rare disorder that involves the hypothalamus, the part of the brain that controls hormone release. Certain hormones are abnormally decreased in Kallmann’s syndrome that lead to a failure to begin puberty. Kallmann’s syndrome is also associated with a decreased or absent sense of smell (anosmia).


Kallmann’s Syndrome is estimated to occur in 1 out of 10,000 children. The disorder primarily affects males, although there have been rare cases of the disease occurring in females. Kallmann’s syndrome can affect children from all ethnic backgrounds.

Signs and Symptoms

Children with Kallmann’s Syndrome usually have the following symptoms:

  • Anosmia (reduced or complete absence of smell)
  • Small penis and small or undescended testicles (testicles are located outside of the scrotum)
  • Infertility Other symptoms may include:
  • Gynecomastia (breast development in males)
  • Single missing kidney
  • Osteoporosis (a thinning and weakening of the bones)
  • Bimanual synkinesis (mirror movements of one hand copying the movements of the other hand)
  • Cleft lip or palate

Possible Causes

The underdeveloped genitalia and infertility of Kallmann’s syndrome are the result of deficient secretion of a hormone called GnRH from the hypothalamus. Normally, the hypothalamus secretes GnRH, and GnRH then instructs a gland in the brain called the pituitary to secrete LH. These hormones are required for puberty to progress. Decreased or absent GnRH also causes reduced levels of other hormones including estrogen and testosterone. The decreased or absent sense of smell in Kallmann’s Syndrome is due to the lack of olfactory neurons (nerve cells in the brain that are responsible for sensing smell). Recent studies demonstrate that GnRH neurons (the nerve cells that secrete GnRH hormone) originate in olfactory tissues and migrate to the hypothalamus. Thus, a problem in the brain’s olfactory area leads to a decreased amount GnRH neurons and deficient GnRH secretion from the hypothalamus. This explains why the absent sense of smell, underdeveloped genitalia, and sterile gonads, seemingly unrelated symptoms, occur together in Kallmann’s syndrome. Kallmann’s Syndrome is primarily an X-linked recessive disease, meaning that it is inherited from the child’s mother through the X (sex) chromosome. This is why boys are affected more than girls. In the rare cases of Kallmann’s Syndrome occurring in females the disease was inherited an autosomal recessive fashion, meaning that the child must inherit two abnormal genes (one from each parent) in order to express the disease. Kallmann’s Syndrome can also occur spontaneously in children without a family history.


Most children with Kallmann’s Syndrome are diagnosed when being evaluated for failure to begin puberty. Testing is usually done to check hormone levels in the blood.


Treatment for children with Kallmann’s Syndrome involves hormone replacement and GnRH injections to help them go through puberty. They may also undergo fertility treatments later in life if they have the desire to have children. There is no cure or treatment for the absent sense of smell. Regular bone density scans, MRI (magnetic resonance imaging) scans, and blood tests may be required to monitor the child.


Children with Kallmann’s Syndrome have a normal life expectancy. Treatment for this disorder is an ongoing process. About 50 % of people treated can achieve pregnancies later in life if so desired. There is an increased risk for development of osteoporosis later in life.

Connect with other parents

In the spirit of community and support, Madisons Foundation offers the unique service of connecting parents of children with rare diseases. If you would like to be connected to other parents of children with this disease, please fill out this brief form.

Patient Support organization for sufferers of Kallmann’s Syndrome. There is currently a fee for membership.

The Pituitary Foundation
This site has general information on Kallmann’s Syndrome, links to other resources, a newsletter, and local support groups.

Keep Kids
This site has general information on Kallmann’s Syndrome.

Google Search for Kallmann's Syndrome

References and Sources

1. 2. Andreoli, Cecil (2001) Cecil Essentials of Medicine 5th ed, Saunders, p. 576 3.