A PAX6 gene polymorphism is associated with genetic predisposition to extreme myopia

Abstract

Purpose: The PAX6 gene is a homeobox gene involved in oculogenesis, ocular growth, and form-deprivation myopia. Our aim was to determine whether PAX6polymorphism at position -12 of intron 9 (IVS9-12C to T, rs667773) is associated with high myopia in Chinese Taiwanese.

Methods: This case-control study compared a study group (n=188) with high myopia whose spherical equivalent was greater than -6.0 D with a control group (n=85) whose spherical equivalent was less than -0.5 D. Genotyping of IVS9-12C to T was conducted by restriction fragment length polymorphism analysis, and results were compared for the two groups.

Results: No significant difference in genotype and allelic frequency at this position between the study and control groups was detected. However, there was a significantly higher frequency of the CC genotype in extremely myopic (greater than -10 D) patients (P<0.001, odds ratio (OR=5.265), confidence interval (CI=2.0342-13.626)). Furthermore, there was a higher frequency of the C allele in the extreme myopia group than in the control group (P=0.002, OR=3.73, CI=1.57-8.81).

Conclusions: The elevated frequency of the CC genotype within the extreme myopia group indicated that the CC genotype could act as a genetic marker, identifying patients predisposed to develop extreme myopia. Varied expression of this genotype may contribute to the genetic predisposition to high myopia in Chinese Taiwanese.