By Teresa Rubio Asensio BSc, MSc (embryologist).
Last Update: 09/17/2014

Kallman syndrome, or de Morsier syndrome, is a congenital failure related to hypogonadotropic hypogonadism, due to a falling within GnRH hormone production (gonadotrophin releasing hormone).

GnRH is one of the hormones that control hypothalamus-pituitary system: this provides the stimulation of the FSH hormone secretion (follicle stimulating hormone) and LH (luteinizing hormone), necessary for a good secretion of sexual hormones to exist.

This GnRH hormone falling can be due to a defect in a gene; for this reason, the syndrome is considered a hereditary disorder that can be passed to the offspring. There are three forms of genetic transmission: recessive (connected to X chromosome), autosomal recessive and autosomal dominant.

How to diagnose the Kallam syndrome

One of the most typical symptoms of this illness is congenital anosmia and hyposmia, which means a partial or total absence of smells perception, due to an incorrect development of the olfactory bulbs.

This illness appears with a frequency of 1 of every 10.000 men, and 1 of every 50.000 women. The men with this syndrome will have a poor sexual development and their fertility could be altered by a lack of testosterone, the male sexual hormone. These people are normally azoospermic or oligozoospermic.


The symptomatic picture can be totally present, or only some of the symptoms can be suffered:

  • Parcial or total anosmia.
  • Micropenis or testicular hypotrophy: incorrect development of the testicles, their size is smaller than normal.
  • Cryptorchidism.
  • Wrong growing during the puberty, when secondary characteristics are absent.
  • Infantilism: these patients have children’s characters that last in the adult life.
  • Kidney abnormalities, unilateral or bilateral kidney aplasia.
  • In some case, moderate mental retardation.
  • Hands and eyeballs involuntary movement.
  • Cleft palate.


For the illness diagnosis, hormonal analysis is used with FSH and LH hormones, as well as with sexual hormones (testosterone).
Olfactory perception is also evaluated, although it is not a really objective test, most of all in case of a partial anosmia.

Another diagnosis test is the GnRH test, which consists of a stimulation with gonadotropins and, later, of a LH spontaneous discharge appraisal.

Before giving a diagnosis, it is necessary to distinguish between the Kallman Syndrome and a normal growth and puberty delay; this difference will be confirmed in time, because any tests before the puberty would give a wrong diagnosis.

The Kallam syndrome

In order to verify if the baby is still in his prepubertal stage, it is enough to observe the absence of secondary characteristics, and to confirm through palpation and ultrasounds a small dimension of the gonads.


These patients can be treated in two different ways, according to the final aim. On one hand, recovering the secondary characteristics, through androgenic therapy: this treatment has the aim of developing and maintaining the secondary characteristics (body hair, beard, mustache, deeper voice, muscular and bone development, etc…). Those appear under hormone replacement therapy with testosterone and hCG. This therapy improves physical activity, libido and erection; the treatment is normally to be followed all life long.

On the other hand, in order to recover fertility, the treatment to be carried out is through repeated GnRH injections (a gonadotropin releasing hormone). This hormone’s presence in men promotes sperm production around the third month. To have this production normalized, the injections will have to be maintained for several months.

Through the administration of hCG (human chorionic gonadotropin), followed by FSH or human menopausal gonadotropin (hMG), the medication supports the increase in testosterone concentration, and spermatogenesis is promoted.

To recover the olfactory senses there is no current treatment.

Authors and contributors

 Teresa Rubio Asensio
BSc, MSc
Master's Degree in Medicine and Reproductive Genetics from the Miguel Hernández University of Elche (UHM). Teacher of different Clinical Embryology courses at the UHM. Member and writer of scientific contents at ASEBIR and ASPROIN. Embryologist specializing in Assisted Procreation at UR Virgen de la Vega. More information