Kallman syndrome is a type of hypogonadotropic hypogonadism, which is also associated with anosmia (absence of smell).
For the normal functioning of our gonads (ovaries in women or testicles in men), it is necessary the functioning of the hypothalamic-pituitary-gonadal axis. When this works correctly, at the level of the hypothalamus (in the brain) a hormone called GnRH is produced, which in turn stimulates the pituitary gland (also at the cerebral level) to produce two other hormones, FSH and LH. These are the ones that will ensure that the ovary produces a correct ovulation and in the testicle a normal formation of sperm (spermatogenesis).
In people with hypogonadotropic hypogonadisms such as Kallman syndrome, there is a defective production of GnRH, so that the rest of the hypothalamic pituitary gonadal axis will not be activated and as a last consequence we will have ovaries or testes without functioning. This can produce a more or less evident symptomatology. In those people with a very severe GnRH deficit, it can occur from birth, with micropenis and cryptorchidism (absence of descent of the testicles from the abdominal cavity) in males. During infancy, the absence of smell may already be evident, and at puberty there may be a total absence of maturation, both in girls and boys. There are some patients in whom there may be a partial production of GnRH and a certain degree of pubertal development. Furthermore, in Kallaman syndrome, congenital anomalies associated with cleft lip, absence of a kidney, deafness, etc., may appear.
The cause of Kallman syndrome is genetic, with different genes involved. Therefore, there is no cure as such. Treatment consists of exogenously giving the body the hormones it needs for proper pubertal development. In women estrogens are administered and in men testosterone, in both cases they will be maintained indefinitely.
In addition, if there comes a time when the patient wishes to have children, the hypothalamic pituitary gonadal axis must be activated with medication. GnRH or FSH and LH can be administered to activate the ovaries and testicles.