The objective of this protocol is to assess response to kisspeptin and gonadotropin-releasing hormone (GnRH) stimulation testing as well as the baseline patterns of luteinizing hormone (LH) secretion in individuals who carry variants in genes related to infertility.

Assignment: All study subjects will undergo the same interventions. Individuals at high risk for infertility (i.e., carry variants in genes related to infertility) will be compared to controls (i.e., those who do not carry variants in genes related to infertility). Delivery of Interventions: * Prior to the inpatient study visit, the subjects will undergo a review of their medical history, physical exam, and screening laboratories. * On the day of the study, the subjects will have an intravenous (IV) line placed and * Undergo up to q10 min blood sampling x 12 hours * Receive a single kisspeptin IV bolus at hour 8 * Receive a single GnRH IV bolus at hour 11