Over 250 disease-causing mutations have been identified in the BEST1 gene to date associated with a broad range of phenotypes, including BVMD, adult vitelliform macular dystrophy, autosomal dominant vitreoretinochoroidopathy (ADVIRC), the MRCS (microcornea, rod-cone dystrophy, cataract, posterior staphyloma) syndrome, retinitis pigmentosa and ARB [9–14]. The gene discussed is BEST1; the disease is MRCS syndrome.