A novel UBIAD1 mutation identified in a Chinese family with Schnyder crystalline corneal dystrophy

Purpose: To identify the molecular defect causing Schnyder crystalline corneal dystrophy (SCCD) in a Chinese family with bilateral corneal abnormalities. Methods: The Chinese SCCD family was subjected to a complete ophthalmic examination that included slit-lamp examination and slit-lamp photography to assess and document the crystalline deposits and arcus lipoides. In vivo laser scanning confocal microscopy and Fourier-domain OCT were also performed on both eyes of SCCD patients. Blood samples were taken for subsequent genetic analysis. The two coding exons of the UbiA prenyltransferase domaincontaining protein 1 (UBIAD1) gene were screened for mutations by direct sequencing. Results: We report on a novel heterozygous mutation of UBIAD1, G98S, in two patients with SCCD. The identified molecular defect cosegregates with the disease and is not found in 50 unaffected individuals. Morphological evaluation on SCCD by in vivo laser scanning confocal microscopy and Fourier-domain OCT highlighted pathological observations at the level of Bowman's membrane and anterior stroma. Conclusion: The newly identified mutation expands the spectrum of mutations in UBIAD1 that may cause pathological corneal cholesterol deposition. Observations by in vivo laser scanning confocal microscopy and Fourier-domain OCT were consistent with the previous histopathologic descriptions of SCCD.