title: Genetic analysis of axial length genes in high grade myopia from Indian population.
abstract: OBJECTIVE
  To study the putative association of Membrane frizzled related protein (MFRP) and Visual system homeobox protein (VSX2) gene variants with axial length (AL) in myopia.
  
  
  METHODS
  A total of 189 samples with (N = 98) and without (N = 91) myopia were genotyped for the MRFP and VSX2 variations in ABI Prism 3100 AVANT genetic analyzer. Genotype/haplotype analysis was performed using PLINK, Haploview and THESIAS softwares.
  
  
  RESULTS
  Fifteen variations were observed in the MFRP gene of which, rs36015759 (c.492C > T, T164T) in exon 5 was distributed at a high frequency in the controls and significantly associated with a low risk for myopia (P = 4.10 ∗ e(- 07) OR < 1.0). An increased frequency for the coding haplotype block [CGTCGG] harboring rs36015759 was observed in controls (31%) than cases (8%) that also correlated with a decreased mean AL (- 1.35085; P = 0.000444) by THESIAS analysis. The 'T' allele of rs36015759 was predicted to abolish the binding site for splicing enhancer (SRp40) by FASTSNP analysis.
  
  
  CONCLUSIONS
  Myopia is a complex disorder influenced by genetic and environmental factors. Our work shows evidence of association of a specific MFRP haplotype which was more prevalent in controls with decreased AL. However, replication and functional studies are warranted to confirm these findings.
authors.affiliation: SN ONGC, Department of Genetics and Molecular Biology, Vision Research Foundation, India ; Birla Institute of Technology & Science (BITS), Pilani, 333 031 Rajasthan, India.
authors.forename: Ferdinamarie
authors.initials: F
authors.lastname: Sharmila
authors.affiliation: Medical Research Foundation, Sankara Nethralaya, Chennai, India.
authors.lastname: Abinayapriya
authors.affiliation: SN ONGC, Department of Genetics and Molecular Biology, Vision Research Foundation, India.
authors.forename: Karthikeyan
authors.initials: K
authors.lastname: Ramprabhu
authors.affiliation: SN ONGC, Department of Genetics and Molecular Biology, Vision Research Foundation, India.
authors.forename: Govindasamy
authors.initials: G
authors.lastname: Kumaramanickavel
authors.affiliation: Preventive Ophthalmology Department, Sankara Nethralaya, Chennai, India.
authors.lastname: R R Sudhir
authors.affiliation: SN ONGC, Department of Genetics and Molecular Biology, Vision Research Foundation, India.
authors.forename: Sarangapani
authors.initials: S
authors.lastname: Sripriya
keywords: Axial length; MFRP; Myopia; Quantitative trait; VSX2