No pathogenic mutations identified in the TGFBI gene in polymorphic corneal amyloid deposition.
OBJECTIVE
To determine whether primary, polymorphic, corneal amyloid deposition is associated with a mutation of the TGFBI gene.


METHODS
Interventional case series of 8 patients. Slit lamp examination of all patients and photodocumentation of 5 patients were performed. Genomic DNA was isolated from buccal mucosal swabs obtained from all patients and all 17 exons of the TGFBI gene were amplified and sequenced.


RESULTS
Multiple polymorphic, refractile deposits were noted throughout the central corneal stroma in all patients. The deposits appeared gray-white on direct illumination and translucent on retroillumination, characteristic of amyloid. In 2 patients, linear, branching opacities, reminiscent of lattice corneal dystrophy, were identified. Histopathologic examination confirmed the presence of stromal amyloid in the cornea of 1 patient who required corneal transplantation for pseudophakic corneal edema. Screening of the entire coding region of the TGFBI gene revealed 4 previously described synonymous substitutions, Leu217Leu, Val327Val, Leu472Leu, and Phe540Phe. A previously unreported missense change, Asp299Asn, was identified in one affected patient but not in her affected sister. No pathogenic mutations, including the Ala546Asp missense mutation previously associated with polymorphic corneal amyloidosis, were identified in any of the patients.


CONCLUSIONS
TGFBI gene mutations were not identified in a series of patients with polymorphic corneal amyloid deposition. As bilateral, discrete stromal amyloid deposits may be dystrophic or degenerative, differentiation between these phenotypically similar conditions is facilitated with the use of molecular genetic analysis.
Aldave
Anthony J
AJ
Jules Stein Eye Institute, University of California Los Angeles Medical Center, Los Angeles, CA 90095, USA. aldave@jsei.ucla.edu
Rayner
Sylvia A
SA
King
Julie A
JA
Salem
Andrew K
AK
Prechanond
Apiradi
A
Hashida
Setsuko
S
Affeldt
John C
JC
Meallet
Mario A
MA
Glasgow
Ben J
BJ
Small
Kent W
KW
Yellore
Vivek S
VS