Disease Directory Best Disease
Ophthalmological

Best Disease

Also known as: Bestrophinopathy, Best vitelliform macular dystrophy, BEST1 maculopathy

Prevalence

1 per 10,000

Onset

Childhood to early adulthood

Type

Autosomal dominant (most cases); autosomal recessive (AVMD)

Gene

BEST1

About Best Disease

Best Disease is a macular dystrophy caused by mutations in the BEST1 gene encoding bestrophin-1, a calcium-activated chloride channel expressed in the retinal pigment epithelium that regulates fluid and ion transport across the RPE-photoreceptor interface. The disease is characterised by the accumulation of lipofuscin-like material beneath the fovea, classically producing a yellowish egg-yolk lesion that progresses through defined stages including vitelliruptive, scrambled egg, and atrophic phases, with central vision declining as atrophy advances. Diagnosis is supported by a markedly reduced or absent Arden ratio on electro-oculography (EOG), which reflects RPE dysfunction even in asymptomatic carriers.

Common Clinical Features

Central vision loss (variable severity and rate of progression) Distortion of central vision (metamorphopsia) Yellowish sub-foveal vitelliform lesion on fundus examination Reduced Arden ratio on electro-oculography Photoreceptor loss overlying areas of RPE atrophy Subfoveal fluid detectable on OCT Relative central scotoma on visual field testing Risk of choroidal neovascularisation (CNV) causing acute vision loss

Clinical Trial Eligibility Tips

What to know before applying to Best Disease trials.

Genetic confirmation of a BEST1 pathogenic variant is important, as EOG abnormalities alone are not sufficient for some trial eligibility criteria.

The stage of the vitelliform lesion (vitelliruptive vs. atrophic) significantly affects eligibility; trials targeting earlier stages may exclude patients with established geographic atrophy.

Report any sudden vision change promptly before screening, as choroidal neovascularisation may require treatment that could affect trial participation.

Patient Resources

Patient Organization

Foundation Fighting Blindness

Visit website ↗

Natural History Registry

My Retina Tracker

Join registry ↗

Orphanet

European reference resource for rare diseases (ORPHA:1227)

View on Orphanet ↗

NORD

National Organization for Rare Disorders

Search NORD ↗

Find recruiting Best Disease trials

Search 500,000+ studies from ClinicalTrials.gov, filtered for Best Disease. Updated daily.

Related Rare Diseases