Phenotype–Genotype Correlation in Patients With Schnyder Corneal Dystrophy

Purpose: The aim of this study was to analyze the corneal morphology features and define mutations in the UbiA prenyltransferase domain–containing 1 (UBIAD1) gene in patients with Schnyder corneal dystrophy from a Polish population. Methods: Five affected and 15 unaffected members originating from 3 families with Schnyder corneal dystrophy were included in the study. Phenotype analysis consisted of visual acuity, slit-lamp biomicroscopy with photography, time domain optical coherence tomography, spectral domain optical coherence tomography, and confocal microscopy. Three patients underwent a penetrating keratoplasty. Corneal buttons obtained from the penetrating keratoplasty were processed for light microscopy. Results: A novel mutation I245N of the UBIAD1 gene was revealed in 1 proband and associated with the phenotype without central corneal opacities. The analysis of the other patients showed the N102S mutation. In vivo corneal morphology analysis using optical coherence tomography and confocal microscopy confirmed the presence of multiple crystalline corneal deposits in all affected corneas. The histological examination revealed multiple empty widenings of the corneal lamellae that could represent lipids removed from the specimen. Conclusions: N102S may also be a mutation hotspot in the Polish population, as in other previously reported populations. Corneal crystals formed a characteristic pattern on optical coherence tomography scans.