Late-onset form of lattice corneal dystrophy caused by Leu527Arg mutation of the TGFBI gene

Purpose. To report two Japanese patients who were clinically diagnosed with late-onset and sporadic lattice corneal dystrophy (LCD) in whom a Leu527Ar g mutation in the TGFBI gene was found. Methods. Molecular genetic analysis was performed on DNA extracted from peripheral leukocytes from the patient s. Exons 4, 11, and 12 of the TGFBI gene were amplified by polymerase chain reaction and directly sequenced. Histopathologic study was performed on th e corneal tissue obtained during deep lamellar keratoplasty (DLK) from one of the patients. Results. Patient 1 was a 74-year-old man who noticed a vis ual disturbance at the age of 72 years. Deep stromal opacities with nodular deposits and thick lattice lines were observed only in the right cornea, a nd DLK was performed. Patient 2 was an 82-year-old man who had LCD (similar in appearance to that in patient 1) in both eyes without visual disturbanc e. Neither of the patients had a family history of corneal problems and had no episode of corneal erosion. A heterozygous single base-pair transition (CTG to CGG, leucine to arginin) was detected in codon 527 of the TGFBI gen e in both patients. No mutation was found in codons 124, 501, 518, 546, or 555. Histopathologically, relatively large amyloid deposits in the deep cor neal stroma and ribbons of amyloid deposits just beneath the Bowman's layer were observed in the corneal tissue of patient 1. Conclusions. Clinical fe atures and pathologic findings of the late-onset form of LCD with an L527R mutation in the TGFBI gene were made clear.