If GnRH is not released correctly by the hypothalamus, located deep within the brain the pituitary, located close by is not able to release the hormones LH and FSH.
No LH and FSH means that the testicles can not grow and produce testosterone and sperm.
No LH and FSH means that the ovaries can not produce oestrogen & progesterone or allow eggs to mature and be released.
So no GnRH means no reproductive hormones and infertility.
If GnRH production is affected early in life it means that puberty does not occur either.
Kallmann syndrome is a known as a secondary hypogonadism condition.
This means the problem is with not with the testicles / ovaries themseleves but with the production of the hormones that should have been released at puberty.
One key hormone called GnRH.
GnRH is not released correctly at the time puberty is due.
In turn this prevents the pituitary gland from releasing two hormones called FSH and LH, collectively called gonadotropins.
Without these gonadotropins the ovaries and testicles remain dormant, puberty does not start or fully complete and no reproductive cycle is possible.
