Purpose: A report of two Japanese brothers with gelatinous drop-like corneal dystrophy, one with and one without the typical gelatinous drop-like region.
Design: Interventional case report and observational case report.
Methods: After penetrating keratoplasty, the corneal button, right eye, of the elder brother, 39 years of age, was stained and examined by microscopy. The M1S1 and BIGH3 genes were examined for mutations using the polymerase chain reaction and direct sequencing. Corneal abnormalities in the younger brother, 37 years of age, were observed.
Results: The elder brother had bilateral gelatinous prominences and band-shaped corneal opacities, whereas the younger brother had only bilateral band-shaped opacities. Histologically, corneal deposits beneath the epithelium stained with Congo red. Molecular genetic analysis revealed that M1S1 was homozygously mutated in both brothers (Q118X).
Conclusion: The Q118X mutation of the M1S1 gene can produce either a gelatinous drop-like region or band-shaped opacities.