Abstract
Abstract: :
Purpose: Refractive error has been shown to be under strong genetic control with a heritability based on twin studies of around 85%. Susceptibility loci have been identified in families with autosomal dominant high myopia. The purpose of this genetic epidemiological study was to identify regions of the genome that contain quantitative trait loci (QTL) for refractive error, as no loci have been identified to date in population samples. Methods: Refractive error in 221 unselected female dizygotic twin pairs from the St Thomas' Adult Twin Registry was obtained using a Humphrey 670 autorefractor, and the spherical equivalent obtained for each sib-pair. A genome-wide screen using around 400 markers was performed. Non-parametric multipoint linkage analyses were undertaken, using SOLAR and regression techniques. Results: Maximum evidence of linkage in the twins was observed at chromosome 11p13 (LOD 5.0), with further loci at chromosomes 3q26 (LOD 3.1)and 4q12 (LOD 4.0). These loci remained significant after analysis using robust generalized linear regression modeling. Weaker evidence of linkage (1.0<LOD<3.0) was also obtained for several other regions. Conclusions:These results, if confirmed in other samples, provide strong evidence of possible susceptibility loci for refractive error, and warrant characterization of QTLs and candidates responsible.
Keywords: refractive error development • linkage analysis • myopia