An autosomal dominant form of retinal degeneration (OMIM:153700) of variable penetration and early onset (age 3-15). It is caused by an accumulation of lipofuscin in the retinal pigment epithelium, resulting in degenerative changes in some patients, and secondary loss of photoreceptor cells, typically by age 40.
Findings Fundoscopic appearance ranges from mild pigment defects to a vitelliform–egg yolk–appearance in the central macula; subsequent degeneration may result in subretinal neovascularisation and haemorrhage, and severe macular scarring.
Molecular pathology Defects of BEST1, which encodes bestrophin, a protein that forms chloride channels and regulates voltage-gated L-type calcium ion channels, cause Best disease.
Synonyms Best macular dystrophy, Best vitelliform macular degeneration, Best’s macular degeneration, macular degeneration—polymorphic vitelline, macular dystrophy—vitelliform—2, vitelliform macular degeneration, vitelliform macular degeneration of Best, vitelliform dystrophy