BEST1 Variant Associated with an Atypical Macular and Peripheral Retinal Phenotype

Retin Cases Brief Rep. 2023 Dec 5. doi: 10.1097/ICB.0000000000001520. Online ahead of print.

Abstract

Purpose: Best vitelliform macular dystrophy (BVMD) is an inherited macular dystrophy associated with over 250 pathogenic variants of the Bestrophin-1 (BEST1) gene. While several of the types of lesions of BVMD are well-described, reports of phenotypic variations associated with rare genetic variants are limited.

Methods: Retrospective case-series performed in 2021 at a tertiary eye care center.

Patients: Three members of one family referred to a tertiary eye care clinic for evaluation of their autosomal dominant macular dystrophy.

Results: Study subjects presented with atypical findings of peripheral schisis-like lesions and atrophy with abnormal electroretinogram (ERG) in addition to typical macular lesions found in BVMD. Genetic analyses identified a heterozygous BEST1 c.227T>A, p.(Ile76Asn) pathogenic variant in all three subjects.

Conclusions: This study represents the first report of the phenotype associated with the c.227T>A, p.(Ile76Asn) BEST1 variant, which - while mentioned twice in the literature - has not been previously described. The phenotype is unique, comprising features of typical BVMD with ERG and peripheral findings, suggestive of a panretinal dysfunction.