A novel TACSTD2 mutation identified in two Chinese brothers with gelatinous drop-like corneal dystrophy

PURPOSE: To identify the molecular defect causing gelatinous drop-like corneal dystrophy (GDLD) in two Chinese brothers and report the morphological evaluation of GDLD by laser scanning confocal microscopy and Fourier-domain optical coherence tomography (OCT). METHODS: Genetic analysis included polymerase chain reaction (PCR) amplification and direct nucleotide sequencing of the coding region of the tumor-associated calcium signal transducer 2 gene (TACSTD2) in DNA from the two brothers and their relatives. Laser scanning confocal microscopy and Fourier-domain OCT were performed on the left cornea of the younger brother. RESULTS: We report a novel in-frame mutation of TACSTD2, c.526_576del 51, in the two brothers with GDLD. The identified molecular defect cosegregated with the disease and was not found in 50 unaffected individuals. The morphological evaluation on GDLD highlighted pathological observations at the level of epithelium and anterior stroma. The epithelial cells of GDLD cornea were irregular in shape and often elongated. Large accumulations of brightly reflective amyloid material was noted within or beneath the epithelium and within the anterior stroma. CONCLUSIONS: The newly identified mutation expands the spectrum of mutations in TACSTD2 that may cause pathological corneal amyloidosis. Observations by in vivo confocal microscopy and Fourier-domain OCT were consistent with the histopathologic descriptions of GDLD.