Figure 2.

Neuroendocrine characteristics of children presenting with delayed or stalled puberty. A, A schematic of the protocol. Details of the protocol are given in Chan et al (20). At the first visit, participants had serum luteinizing hormone (LH) measured to assess spontaneous pulsatility overnight and to chart responses to kisspeptin and gonadotropin-releasing hormone (GnRH). Participants then received exogenous pulsatile GnRH to enhance pituitary responsiveness to GnRH. They then returned for a second visit to measure LH secretion in response to kisspeptin and GnRH after this pituitary “priming.” B, Results for participant A, a “kisspeptin nonresponder.” C, Results for participant B, a “kisspeptin responder.”