Gonadotropin-releasing hormone (GnRH) is a hormone that is normally released (secreted) approximately every two hours in episodes called pulses. In response to pulsatile GnRH exposure, the pituitary gland secretes hormones called gonadotropins (luteinizing hormone, or LH, and follicle-stimulating hormone, or FSH), which either 1) stimulate the testicles to produce testosterone and develop sperm in men or 2) stimulate the ovaries to produce estrogen and develop a follicle to ovulate in women. Normal levels of estrogen and testosterone are required for fertility. In people with isolated hypogonadotropic hypogonadism (IHH), also known as "congenital GnRH deficiency", there is either a decrease or total absence of GnRH secretion, or an inability of the body to respond normally to this hormone, so that the levels of gonadotropins and testosterone or estrogen are low. Some patients with IHH also have a reduced sense of smell (anosmia) and may be diagnosed with Kallmann Syndrome. Other related conditions, such as constitutional delay of puberty (CDP) and functional hypothalamic amenorrhea (HA) may also be due to abnormal GnRH action. This is a study of patients who may have a disorder related to GnRH secretion.

The purpose of this study is to identify men, women, and adolescents with disorders of GnRH secretion or action, in order to find out the spectrum of abnormalities in these disorders and what may cause them. This will help us to better understand how GnRH secretion helps to regulate puberty and fertility. You may be eligible if you have been diagnosed with IHH/Kallmann syndrome, CDP, HA, or have experienced late or absent puberty, or normal puberty with fertility problems in adulthood that are related to decreased levels of LH and FSH.

All subjects participating in this study, and their family members, are encouraged to participate in our related study, "The Molecular Basis of Inherited Reproductive Disorders," in order to maximize what we can learn from our findings. However, participation in both is not required.

Important Information and Instructions for Patients and Physicians

  • For patients who have an appointment at the NIH:
    • Navigate through all items of the menu on your left to learn more about the investigations, and to find essential instructions for preparing for your NIH visit, including travel information.
    • Once enrolled, please be sure to review the Preparing for your NIH Visit and Planning your travel to the NIH sections.
  • For physicians who would like to refer a patient to the NIH, please Contact Us.
    • You will be asked to obtain permission from the patient (or their parent/guardian) to send us all relevant medical records from the time of diagnosis, including growth charts and copies of MRIs or other studies.
Please Contact Us if you have any questions or concerns.