IGF1 and myopia: [24] Recently, many genetic studies showed that rs12423791 or rs6214 polymorphisms in IGF-1 were significantly associated with high or extreme myopia in Caucasian and Chinese populations; [25,26] however, another study demonstrated that IGF-1 gene rs12423791 and rs6214 polymorphisms were not associated with high myopia, [27,28] even though a number of single nucleotide polymorphisms (SNPs) in IGF-1 have been reported.