Exclusion of the TGFBI gene in Polymorphic Corneal Amyloidosis

Abstract

Abstract: : Purpose: To determine whether primary polymorphic corneal amyloid deposition is associated with mutations in the TGFBI (keratoepithelin) gene. Methods: : Interventional case series of 6 patients. Slit lamp examination of all patients and photodocumentation of 3 patients. Genomic DNA was isolated from buccal mucosal swabs obtained from all patients and exons 4, 11, 12 and 14 of the TGFBI gene were amplified and sequenced. Results:Multiple polymorphic, refractile deposits were noted throughout the central corneal stroma in all affected patients. The deposits appeared gray–white on direct illumination and translucent on retroillumination, characteristic of amyloid deposits. Screening of TGFBI exons 4, 11, 12 and 14 revealed one patient who was heterozygous for the Leu472Leu polymorphism, and 2 other unrelated patients who were compound heterozygous for the Leu472Leu and the Phe540Phe polymorphisms. No other nucleotide changes were identified. Conclusions:In contrast to recent reports documenting mutations in the TGFBI gene in patients with polymorphic amyloid deposits, no mutations were identified in the exons of the TGFBI gene in which mutations resulting in corneal amyloid deposition have been identified.

Keywords: degenerations/dystrophies • gene screening • cornea: stroma and keratocytes