KISS1 and precocious puberty: This change in kisspeptin levels at the onset of puberty is also consistent with the findings of Yang et al. (16), who showed that girls with idiopathic central precocious puberty had higher serum levels of kisspeptins than normally developing controls and that, after treatment, these concentrations fell below pre-treatment levels, suggesting a role of peripheral kisspeptin concentrations on pubertal onset in this sex.