High-resolution analysis of DNA copy number alterations in patients with isolated sporadic keratoconus

PURPOSE To determine whether patients with sporadic, non-familial keratoconus and no pathogenic mutations in the visual system homeobox 1 (VSX1) gene have evidence of chromosomal copy number alterations. METHODS Twenty Saudi Arabian patients with isolated keratoconus, no family history of the disease and no mutations in VSX1 were recruited. Additionally, 10 ethnically-matched healthy controls were also recruited for this study. We screened patients for chromosomal copy number aberrations using the Agilent Human Genome CGH 244A Oligo Microarray Chip. RESULTS None of the keratoconus patients screened had evidence of chromosomal copy number alterations when compared to normal ethnically matched controls. CONCLUSIONS Chromosomal deletions and/or duplications were not detected in any of the patients tested here. Other chromosomal imbalances such as translocations, inversions, and some ploidies cannot be detected by current array CGH technology and other nuclear genetic or epigenetic factors cannot be excluded as a possible contributing factor to keratoconus pathogenesis.