Conversely, the mutations and SNPs of four genes were less prevalent in patients with CPP than in controls: the polymorphism (55648176) in the KISS1 gene [39], the AC haplotype of Lin28B in two positions (SNPs rs4946651, RS369065) [43], and the cytochrome P450 CYP1B1 Eco571 variant (V432 L) [44]. This evidence concerns the gene CYP1B1 and central precocious puberty.