IGF2 and central precocious puberty: However, some SNPs combinations had significant effect on parameters, including age of pubarche in the CPP patients [IGF-2(6093) + IGFBP-3] and IGF levels [IGF-1(1770) + IGFBP-3] (p = 0.038), [IGF-1(6093) + IGFBP-3] (p = 0.013), and [IGF-2(3580) + IGFBP-3] (p = 0.036) [52].