Corneal Plana-Like Phenotype With Peripheral Scleralization Associated With a Pathogenic Variant of PITX2 : A Case Report

PURPOSE

The aim of this study was to report a case of corneal plana-like phenotype with bilateral peripheral scleralization associated with a PITX2 pathogenic variant.

METHODS

Clinical findings were obtained by ophthalmologic examination. Molecular diagnosis was performed by whole-exome sequencing in the patient and his parents.

RESULTS

A 12-month-old male patient present with bilateral peripheral corneal scleralization, corneal plana-like phenotype, and iris hypoplasia. The genetic analysis revealed a de novo PITX2 pathogenic variant (c.323G>A, p.R108H).

CONCLUSIONS

PITX2 c.323G>A (p.R108H) can be associated with a unique corneal plana-like phenotype with peripheral scleralization, and thus, PITX2 should be targeted in genetic testing of this specific phenotype.

The IC3D classification of the corneal dystrophies

BACKGROUND

The recent availability of genetic analyses has demonstrated the shortcomings of the current phenotypic method of corneal dystrophy classification. Abnormalities in different genes can cause a single phenotype, whereas different defects in a single gene can cause different phenotypes. Some disorders termed corneal dystrophies do not appear to have a genetic basis.

PURPOSE

The purpose of this study was to develop a new classification system for corneal dystrophies, integrating up-to-date information on phenotypic description, pathologic examination, and genetic analysis.

METHODS

The International Committee for Classification of Corneal Dystrophies (IC3D) was created to devise a current and accurate nomenclature.

RESULTS

This anatomic classification continues to organize dystrophies according to the level chiefly affected. Each dystrophy has a template summarizing genetic, clinical, and pathologic information. A category number from 1 through 4 is assigned, reflecting the level of evidence supporting the existence of a given dystrophy. The most defined dystrophies belong to category 1 (a well-defined corneal dystrophy in which a gene has been mapped and identified and specific mutations are known) and the least defined belong to category 4 (a suspected dystrophy where the clinical and genetic evidence is not yet convincing). The nomenclature may be updated over time as new information regarding the dystrophies becomes available.

CONCLUSIONS

The IC3D Classification of Corneal Dystrophies is a new classification system that incorporates many aspects of the traditional definitions of corneal dystrophies with new genetic, clinical, and pathologic information. Standardized templates provide key information that includes a level of evidence for there being a corneal dystrophy. The system is user-friendly and upgradeable and can be retrieved on the website www.corneasociety.org/ic3d.