The similar distribution of SNPs of the genes in the IGF-1 axis between CPP and control groups were in contrast to the skewed distribution of mutations and SNPs of four genes that were more prevalent in patients with CPP: the autosomal dominant GPR54 R386P mutation [37, 38], several polymorphisms (55,648,184; 55,648,186) in the KISS1 gene [39], the intron 4 (TTTA)13 repeat in the cytochrome P450 19A1 gene CYP19A1 gene [40], and a haplotype in the 5′ promoter region of the LH β gene [41]. Here, IGF1 is linked to central precocious puberty.