Association of the PAX6gene with extreme myopia rather than lower grade myopias

AimsTo investigate the association of the paired box gene 6(PAX6) with different severities of myopia.MethodsA total of four haplotype-tagging single-nucleotide polymorphisms (SNPs; rs2071754, rs3026354, rs3026390 and rs628224) and two previously reported SNPs (rs644242 and rs662702) in the PAX6gene were analysed in a Hong Kong Chinese cohort of 1288 myopia subjects (including 252 extreme myopia, 277 high myopia, 393 moderate myopia and 366 mild myopia) and 791 no myopia controls. Allelic association analyses were performed for individual SNPs in different subgroups of myopia and in combined myopia, followed by a meta-analysis of our current data with reported data on PAX6in myopia.ResultsThe association of tagging SNPs rs2071754 and rs644242 with extreme myopia could not withstand multiple correction (rs2071754: OR=1.25, P value=0.031; rs644242: OR=1.33, P value=0.032). In the meta-analysis, rs644242 showed an enhanced, significant association with extreme myopia (OR=1.27, 95% CI 1.10 to 1.46, P value=0.001; I2=0%). In contrast, there was no significant association between the PAX6SNPs and high, moderate or mild myopia. No linear correlation was found between the PAX6SNPs and axial length.ConclusionThis study provides additional evidence suggesting that the PAX6SNP rs644242 is associated with extreme myopia but not lower grade myopia. Thus, PAX6may be implicated in the development or progression into severe myopia. Further longitudinal studies are warranted.