Association of visual system homeobox gene polymorphisms with the risk of sporadic keratoconus / 中华实验眼科杂志

ABSTRACT

Background Keratoconus is a bilateral,noninflammatory,gradually progressive corneal disorder characterized by progressive thinning and steepening of the central cornea.It is significant to investigate keratoconusrelated pathogenic gene for elaborating the pathogenesis and establishing early diagnosis standard and taking clinical measurement.Objective The aim of the study was to explore the relationship of visual system homeobox gene (VSX1) polymorphism and the risk of sporadic keratoconus.Methods This study was approved by Ethic Commission of First Hospital of Xi' an.Written informed consent was obtained from each subject prior to enrollment.A case-controlled study was conducted.One hundred and one Han nationality patients with sporadic keratoconus were included in this study.These keratoconus patients were clinically diagnosed by slit lamp examination and corneal tomography.Single nucleolide polymorphism (SNP) of VSX1 gene was assayed and classified using the MassARRAY SNP technique.Demography and relevant risk factors were collected from each subject by questionnaire.Eighty healthy volunteers served as controls.Chi-square test and Binary logistic regression were used to evaluate the difference in the distribution of allele frequency and genotype frequency and to analyze the association with keratoconus risks.Results SNP of two genes was found in the Chinese Han population (rs743018 (c.843+140 C＞T) and rs6138482(R217H C＞T)).There were no significant differences in the genotype frequency and allele frequency of the SNP of two genes in the keratoconus group in comparison with the normal control group (P＞0.05).After adjustment by age and sex,SNP of two genes was not significantly associated with the risk of keratoconus (regression modelrs743018 (C＞T) adjustedP=0.35,OR=0.72,95％ CI0.37-1.43 ;rs6138482 (C＞T) adjustedP =0.48,OR=0.76,95％ CI0.35-1.64).Conclusions Gene polymorphisms of rs743018(c.843+140 C＞T) and rs6138482(R217H C＞T) in the Chinese Han population is not associated with the risk of keratoconus.Due to the racial difference in genotype and allele frequency,the role of the VSX1 gene in the pathogenesis of keratoconus still remains controversial,and further study needs to be developed.