BEST1 and MRCS syndrome: Over 250 variants in the bestrophin-1 gene, BEST1, are associated with a group of retinal degenerative diseases collectively known as bestrophinopathies [Best disease, autosomal dominant vitreoretinochoroidopathy, retinitis pigmentosa (RP), autosomal recessive bestrophinopathy (ARB)] (Burgess et al., 2008).