Keratitis Fugax Hereditaria Associated With a Novel NLRP3 Mutation in a Non-Finnish Patient

Abstract

Purpose: The aim of this study was to report a novel heterozygous variant c.1712G>T (p.Gly571Val) in the nucleotide-binding domain, leucine-rich repeat family, pyrin domain–containing 3 gene (NLRP3) in a previously unreported non-Finnish individual with keratitis fugax hereditaria (KFH). Methods: Ophthalmologic examination of the proband was performed with slit-lamp biomicroscopy and anterior segment optical coherence tomography. Saliva was collected as a source of DNA, after which targeted exome sequencing of candidate genes was performed using a commercially available panel. Identified presumed pathogenic variants were confirmed by Sanger sequencing. Results: Slit-lamp examination of the 52-year-old female proband revealed peripheral arcus-like degeneration and bilateral central corneal opacification, observed on anterior segment optical coherence tomography to involve the anterior half of the corneal stroma. Examination of the proband's parents revealed clear corneas in each eye. Genetic testing of the proband identified the presence of a novel heterozygous NLRP3 missense mutation (c.1712G>T, p.Gly571Val), which was confirmed by Sanger sequencing. This mutation was absent in the proband's parents. Conclusions: Although KFH has been reported only in individuals of Finnish descent and only in association with a missense mutation in exon 1 of NLRP3, we report an individual of non-Finnish descent with KFH associated with a novel heterozygous variant in exon 2 of NLRP3. Thus, ophthalmologists should be aware of the ethnic and genetic heterogeneity associated with KFH.