New Evidence on BEST1 Genetic Variant Identified in a Patient with Best Vitelliform Macular Dystrophy Phenotype

Case Report

J Ophthalmol & Vis Sci. 2021; 6(3): 1054.

New Evidence on BEST1 Genetic Variant Identified in a Patient with Best Vitelliform Macular Dystrophy Phenotype

Falah R¹*, Distefano LN¹, Abuli-Vidal A², Garcia Arumi J¹ and Boixadera A¹

1Retinal Department, Vall d’Hebron University Hospital, Barcelona, Spain

2Genetic Department, Vall d’Hebron University Hospital, Barcelona, Spain

*Corresponding author: Falah R, Retinal Department, Vall d’Hebron University Hospital, Passeig de la Vall D’Hebron, 119, 08035, Barcelona, Spain

We acknowledge Rachel Boixadera’s help in the English Editing of the case report.

Received: July 22, 2021; Accepted: August 13, 2021; Published: August 20, 2021

Abstract

Best Disease (BD), also known as Best Vitelliform Macular Dystrophy (BVMD), represents an inherited autosomal dominant macular dystrophy with a juvenile age of onset [1].

It is a phenotypically heterogeneous, bilateral condition that affects the retina and Retinal Pigment Epithelium (RPE) caused by pathogenic variants in the BEST1 gene located on chromosome 11q12-13 [2,3].

Typical fundus findings in BD are egg yolk-like, round or oval, lesions seen in the macula, and affected eyes may demonstrate various clinical stages, ranging from the previtelliform stage to Choroidal Neovascularization (CNV) [4]. The macular appearance in all stages is deceptive, as most patients maintain relatively good visual acuity throughout the course of the disease.

Patients commonly experience visual compromise in early adulthood, although the age of onset can range from childhood to late adulthood [3] and most patients with BD maintain good vision in at least one eye. The presence of subretinal fluid or CNV has been associated with a poorer visual prognosis [4].

In this case report, we describe a patient with clinical features suggestive of Best disease. We discuss the differential diagnosis and we present the multimodal imaging of the retina used for both the diagnosis and follow up. We also report a genetic study that demonstrates more evidence on a novel genetic variant in the BEST1 gene. The same genetic mutation has been recently reported as a novel variant in a single patient with BVMD [5].

Keywords: Best vitelliform macular dystrophy; Maculopathy; Retina; Genetic variant

Case Presentation

A 25-year-old woman originally from Uruguay was referred to our retinal department with the diagnosis of bilateral Central Serous Chorioretinopathy (CSC). The onset of the symptoms was subacute: the patient had noticed mild blurring of her vision in both eyes with difficulty in focusing but without metamorphopsia, during the previous year.

Her ocular history was insignificant. However, both her father and brother had macular problems of unknown origin.

On examination, best-corrected visual acuities at distance were 20/30 in the right eye and 20/50 in the left eye. Intraocular pressures by Goldmann tonometer were normal.

Anterior segment examination was unremarkable in both eyes. Funduscopic examination demonstrated normal-appearing optic disks and retinal vasculature. In the posterior pole of both eyes (Figure 1), subretinal fibrosis was observed in the central macula with shallow serous retinal detachment that extended inferiorly. There was an orange-yellowish lipofuscin deposit temporal to the macula. The peripheral retina had a hammered metal appearance. There was no evidence of hemorrhage.