Association of WNT7B and RSPO1 with Axial Length in School Children

To evaluate the association between single-nucleotide polymorphisms (SNPs) in the ZC3H11B, RSPO1, C3orf26, GJD2, ZNRF3, and WNT7B genes and myopia endophenotypes in children. Seven SNPs identified in previous genome-wide association studies of axial length (AL) were genotyped in 2883 Southern Han Chinese children. Multiple linear regression analyses were conducted to evaluate the genotype association with AL, spherical equivalent (SE), corneal curvature (CC), and central corneal thickness (CCT). Two SNPs-namely, rs12144790 in RSPO1 (allele T, P = 0.0066, β = 0.062) and rs10453441 in WNT7B (allele A, P = 8.03 × 10-6, β = 0.103)-were significantly associated with AL. The association of rs4373767 in ZC3H11B (allele C, P = 0.030, β = -0.053) could not withstand the correction for multiple testing. WNT7B rs10453441 showed a strong association with CC (P = 1.17 × 10-14, β = 0.053) and with CCT (P = 0.0026, β = 2.65). None of the tested SNPs was significantly associated with SE. The C allele of SNP rs12321 in ZNRF3 was associated with CC (P = 0.0060, β = -0.018). This study revealed that the RSPO1 SNP rs12144790 was associated with AL, whereas WNT7B rs10453441 was associated with AL, CC, and CCT in children. A novel association between ZNRF3 rs12321 and CC was discovered. Our data suggest that the RSPO1 and WNT7B genes might exert their effects on multiple aspects of eye growth during childhood. Potential differences in the genetic profiles of AL between children and adults should be explored in larger cohorts.