Objective: To investigate the genetic feature of Schnyder corneal dystrophy identified in a four-generation Chinese family.
Method: Ophthalmologic examinations were performed in 3 affected members and 2 unaffected members of a family with Schnyder corneal dystrophy and controls. Genomic DNA was extracted from peripheral blood. The coding regions, 3'UTR and 5'UTR of UBIAD1 gene from all samples were screened by polymerase chain reaction (PCR) and direct DNA sequencing using the primers designed according to the sequence of UBIAD1, and comparatively analyzed with data from Genebank.
Result: The family has 15 members over 4 generations with similar signs and symptoms among proband and affected members. All affected members of the family demonstrated central discoid crystalline deposition with arcus lipoide. Confocal microscopy examination showed multiple depositions of crystalline materials in anterior stroma. OCT showed the high reflective material localized within the anterior stroma. A missense mutation c.305A > G in 1 exon of UBIAD1 gene resulting in a substitution of Asparagine to Serine at codon 102 (p.Asn102Ser) was found in all affected members of the family who were clinically diagnosed as Schnyder corneal dystrophy while not in the unaffected members of the family and controls.
Conclusion: The missense mutation c.305A > G(p.Asn102Ser) of UBIAD1 gene may cause the disease of the family. Gene screen can assist clinicians in making definitive diagnosis, presymptomatic diagnosis and prenatal diagnosis.