Phenotypic expansion of KCNJ13-associated snowflake vitreoretinal degeneration

ABSTRACT

Introduction: An 18-year old highly myopic woman presented with bilateral retinoschisis associated with a unilateral macular hole in the right eye and vitreomacular traction in the left eye.

Methods: Genetic studies disclosed a heterozygous pathogenic variant in the KCNJ13 gene was identified (c.484C>T (p.Arg162Trp)), consistent with a diagnosis of snowflake vitreoretinal degeneration (SVD).

Results: While there were no corneal guttata, juvenile cataracts, or perivascular sheathing in this case, salient features of SVD included a fibrillar vitreous structure, crystalline retinopathy, and flattened optic nerves. The patient developed a FTMH in the left eye at 17 months follow up, followed by a rhegmatogenous retinal detachment (RRD) requiring 2 surgical repairs.

Conclusion: This case expands on the spectrum of clinical features in SVD, including retinoschisis and FTMH. It also characterizes optical coherence tomography findings in this rare disease entity. We emphasize the importance of using panel-based genetic testing to clinically distinguish and further define atypical vitreoretinopathies.

KEYWORDS:

• Snowflake vitreoretinal degeneration
• inherited vitreoretinopathy
• retinoschisis
• macular hole
• pediatric retina
• ophthalmic genetics

Acknowledgements

Ophthalmic Photography Department, Bascom Palmer Eye Institute, University of Miami School of Medicine (Miami, Florida).

Disclosure statement

Dr. Berrocal consultant for: Alcon, Zeiss, Dorc, Novartis, Aeerie, ProQr, RegenXbio.

Statement of ethics

The authors have no ethical conflicts to disclose. Approval from the ethics committee was not required. This case report did not meet the federal definition of human subject research.

Authorship

All authors attest that they meet the current ICMJE criteria for Authorship.

Additional information

Funding

The Department of Ophthalmology receives grant support from the NIH Center Core Grant P30EY014801 (Bethesda, Maryland) and the Research to Prevent Blindness Unrestricted Grant (GR004596) to the University of Miami.