Abstract
Purpose: :
Keratoconus (KC) is a corneal dystrophy with an incidence of approximately 1 in 2,000 in the general population. It is a major cause of visual disability worldwide and a leading cause for cornea transplantation in Western developed countries. Segregation analysis supports a genetic basis for this disease. A recent study reported three novel single nucleotide polymorphisms (SNPs) with amino acid changes in VSX1 gene (L159M, R166W and H244R) associated with KC disorder by direct sequencing.
Methods: :
In an attempt to confirm these observations, we genotyped the same polymorphisms in a case–control panel (74 KC patients and 73 normal controls) and a KC familial panel (444 individuals from 78 families) using the TaqMan Allelic Discrimination assay (L159M and R166W) and the RFLP assay (H244R).
Results: :
We observed no polymorphisms of R166W, neither in the case–control panel nor in the familial panel. We observed 3 heterozygous of H244R polymorphism only in familial KC panel. Among them, 2 heterozygous subjects were affected MZ and the other was an unaffected. We observed 1 heterozygous of L159M polymorphism in the normal group of the case–control panel, and 5 heterozygous in familiar KC panel with 3 affected and 2 unaffected.
Conclusions: :
Statistical analysis does not support the association of these VSX1 SNPs with KC disorder in our sample sets. Our observation is contradict with the previous report.
Keywords: keratoconus • mutations • genetics