Independent association of whole blood miR-328 expression and polymorphism at 3'UTR of the PAX6 gene with myopia.

Purpose: This study aimed to find associations between miR-328 expression in whole blood, polymorphism at 3'UTR of the PAX6 gene (paired box homeotic gene 6) and myopia.

Methods: We evaluated 451 individuals (142 individuals with low, 49 with moderate and 13 with high-degree myopia, and 247 healthy individuals). DNA and RNA were extracted from peripheral blood samples. Expression of miR-328 was assessed and genotyping of single-nucleotide polymorphisms (SNPs) of the PAX6 (rs662702) performed using the Applied Biosystems 7900HT Real-Time Polymerase Chain Reaction System.

Results: Moderate and high degree myopia showed significant differences between TT and CT genotypes of the PAX6 gene (p < 0.001). In the myopia group, 71.4% of the subjects had the TT genotype and 28.6% had the CT genotype; meanwhile in the control group, 97.1% had the TT genotype and 2.9% had the CT genotype. The odds ratio of having moderate and/or high degree myopia for individuals with the CT genotype was 13.6 (2.865-64.55) 95% CI versus TT genotype (p = 0.001). MiR-328 results showed that ∆Ct values differed statistically significantly between the myopia and control groups. Patients with myopia in the peripheral blood cells had a higher expression of miR-328 than controls (p < 0.05).

Conclusions: Significant differences were detected between the PAX6 gene (rs662702) TT and CT genotypes in moderate and high degree myopia; the risk C allele increased the risk for myopia. The expression level of miR-328 in peripheral blood cells was higher in patients with myopia than controls. We did not find the association between expression of mir-328 in the peripheral blood cells and PAX6 gene (rs662702) polymorphism comparing myopia and control groups.