Kallmann syndrome is a rare sex-related condition that occurs in less than 0.025% of the population. Its occurrence is more common in males than in females. It is an X-linked trait and affects the adrenal glands, which causes a deficiency of important endocrine hormones that are needed in order for proper sexual development to occur. Although at first hard to detect, if the condition is left untreated, the absence or underdevelopment of secondary sex organs can occur, and infertility may also result.
It is difficult to detect whether a person is suffering from Kallmann syndrome mainly because the symptoms are not evident until the patient is old enough to reach puberty. The mechanisms underlying the basis of the onset of puberty are still being studied, so the effects of hormones in relation to puberty are not fully understood. When Kallmann syndrome is suspected, a blood sample analysis is needed for a proper diagnosis.
Sex hormones are a one type of steroid hormones that are released by signals from the hypothalamus within the brain. During puberty, the hypothalamus will release gonadotropin-releasing hormone (GnRH), which will then release gonadotropin into the bloodstream. The release of this hormone starts a cascade of events that helps to start the process of puberty. The release of gonadotropin will act as a signal to the adrenal glands to release sex hormones estrogen and testosterone, which help the onset of puberty to occur.
In people suffering from Kallmann syndrome, the adrenal glands malfunction due to decreased levels of GnRH. The low levels of GnRH mean that there are lower levels of gonadotropin released. This, in turn, causes little or no release of sex hormones into the bloodstream.
The main problem caused by Kallmann syndrome is the delayed onset of puberty and the development of secondary sex characteristics. This can be offset if the patient receives regular sex hormone injections to counteract the decreased sex hormone levels. When males are treated with testosterone and females are treated with estrogen, this allows for the development of normal secondary sex characteristics.
Some patients with Kallmann syndrome have problems with fertility. This can be combated by another form of hormone therapy, which makes the patient temporarily fertile. Another common condition associated with this syndrome is the inability to distinguish between different types of odors, a condition known as anosmia.