Since members of the IGF family are involved in the onset of puberty, we aimed to identify polymorphisms in insulin (INS), IGF-1, IGF-2, IGF-1 receptor (IGF1R), IGR2R, and IGF binding protein 3 (IGFBP-3) that may alter the risk for development of central precocious puberty. Here, INS is linked to precocious puberty.