Evaluation of Candidate Genes for Myopia Susceptibility in Indian Population

Abstract

Purpose: : Myopia is a complex disorder of the eye responsible for visual impairment with a high heritability estimate and concordance rate. In the current study, we have analyzed the genetic determinants of myopia in Indian cohort.

Methods: : A detailed ophthalmic examination in a cohort of 102 myopes defined with > -6 diopter spherical error and unrelated healthy controls (n=93) was performed in the study cohort for genetic association study. Direct sequencing of MFRP, CHX10 and signal peptide region of TGF ar beta 1 gene was done to identify the possible genetic risk factor for myopia. Additionally, an affymetrix based approach was used to localize the candidate region in an autosomal dominant myopia pedigree from Indian population. Analysis of the genotypes was performed using the Alohomora software and linkage analysis was done using GENEHUNTER, v 1.3

Results: : We did not observe any significant association with myopia in the candidate genes. of Myopia. However, the C-C haplotype for codon 10 and 25 polymorohism in the signal peptide region of the TGF beta1 gene was distributed significantly more in the controls (p = 0.0239) and associates with axial length parameter (p= 0.002). Fifteen variations were identified in the MFRP gene (7 novel variations and 8 known SNPs) . However we did not identify any significant association with the MFRP and CHX10 genes. The current study did not identify any significant association with the candidate genes TGFbeta1, MFRP and CHX10 for myopia in Indian population. Linkage analysis by Gene hunter gave positive npl > 1.2 on chromosome 11,8 and 14.

Conclusions: : We did not identify any disease associated variations in the candidate genes for myopia in the Indian cohort. Finner characterization of the SNPs in the candidate regions, identified in the study is in progress.

Keywords: myopia • genetics • candidate gene analysis