Best vitelliform macular dystrophy (Best disease) is characterized by the presence of a vitelliform macular lesion leading to the classic egg-yolk appearance in genetically predisposed individuals.1 The BEST1 gene (formerly known as VMD2), which encodes the protein bestrophin-1 and is located on the 11q12-q13, is responsible for this disease.2 Bestrophin is a transmembrane protein found on the basolateral side of retinal pigment epithelium (RPE) cells3 and is responsible for calcium-dependent chloride transport.4 This evidence concerns the gene BEST1 and Best vitelliform macular dystrophy.