Purpose
To report the clinical, histopathologic, and genetic features of a variant of lattice corneal dystrophy (LCD) associated with two pathogenic mutations in the TGFBI gene.
Methods
Clinical characterization was performed by slit lamp examination and in vivo confocal microscopic imaging (IVCM). Histopathologic characterization was performed with light microscopic examination of an excised corneal button and a peripheral blood sample was collected for TGFBI screening.
Results
A 42-year-old woman complained of progressive photophobia and decreased visual acuity in both eyes. Slit lamp examination demonstrated linear and branching opacities in the mid and posterior corneal stroma, corresponding to hyperreflective opacities noted on IVCM and amyloid deposition noted on histopathologic examination of an excised corneal button. TGFBI screening revealed two previously reported heterozygous missense mutations: c.337G>A (p.(Val113Ile)) in exon 4 and c.1673T>C (p.(Leu558Pro)) in exon 12.
Conclusions
The p.(Leu558Pro) mutation results in an alteration of the granular corneal dystrophy phenotype associated with the p.(Val113Ile) mutation in an individual heterozygous for both, resulting in a variant form of lattice corneal dystrophy. This represents only the second report of the alteration of the phenotype of a TGFBI dystrophy by a second, non-homozygous pathogenic mutation, and thus provides insight into the phenotype-genotype correlation of the TGFBI dystrophies.