A Case of Lattice Corneal Dystrophy Type 1 Initially Showing Phenotypic Characteristics of Granular Corneal Dystrophy Type 2 in One Eye and Dot and Map Lesions in the Contralateral Eye

Purpose: Lattice corneal dystrophy type 1 (LCD1) typically presents with linear lesions in the corneal stroma. We report an atypical case of a patient with LCD type 1, who exhibited granules and deep lines resembling granular corneal dystrophy type 2 (GCD2) in one eye and maps and dots resembling epithelial basement membrane dystrophy (EBMD) in the contralateral eye.Case summary: A 22-year-old woman presented with progressive visual disturbances. Slit lamp examination revealed subepithelial granular opacities and linear lines in one eye and maps and dots in the other eye. Peripheral blood was collected, and genomic sequencing of <i>transforming growth factor β-induced protein</i> (<i>TGFBI</i>) was performed to identify any mutations. The sequencing revealed a heterozygous Arg124Cys (R124C) mutation, which is diagnostic for LCD1. Serial examinations over the years indicated a spontaneous reduction in the granular deposits and an increase in the lattice component, illustrating the progression of the phenotypic traits associated with LCD.Conclusions: Although the R124C mutation of <i>TGFBI</i> is known to be associated with LCD1, it can manifest clinical characteristics similar to GCD2 or EBMD in the early stages of the disease. Genetic testing is recommended for definitive diagnosis in cases of <i>TGFBI</i>-related corneal dystrophies.