To investigate the genetical precursors of cataract development the next groups were included: patients suffering from cataract (96) and 96 healthy persons. The determination of γ-crystallin polymorphism (G(-47)-->A) (rs2289917) was provided using PCR method and further analyses of restriction fragment length polymorphism. These allelic variants have the significant different: G/G--35.37%, G/A--53.66%, A/A--10.98%, and G/G--55.06%, G/A--35.96%, A/A--8.99% comparing with the control group (P = 0.03, by χ2-test). While investigating the level of expression of γ-crystallin gene (CRYGB) in platelets, showed that the quantity of mRNA in homozygotes G/G in 3.9 times (P < 0.05) higher than in carriers of A allele (genotype G/A and A/A). This paper shows the significant difference in distribution of CRYGB promoter (G(-47)-->A) genotypes in patients with cataract compared to the control group. Furthermore, here we provide the data concerning its functional meaning: level of mRNA expression of crystallin is different in carriers of various CRYGB promoter (G(-47)-->A) genotypes.