Identification of the PROM1 Mutation p.R373C in a Korean Patient With Autosomal Dominant Stargardt-like Macular Dystrophy

Stargardt-like macular dystrophy 4 (STGD4) is a rare macular dystrophy characterized by bull's eye atrophy of the macula and the underlying retinal pigment epithelium. Patients with STGD4 show decreased central vision, which often progresses to severe vision loss. The PROM1 gene encodes prominin-1, which is a 5-transmembrane glycoprotein also known as CD133 and is involved in photoreceptor disk morphogenesis. PROM1 mutations have been identified as genetic causes for STGD4 and other retinal degenerations such as retinitis pigmentosa. We report a case of STGD4 with a PROM1 p.R373C mutation in a Korean patient. Ophthalmic examinations of a 38-yr old man complaining of decreased visual acuity revealed bilateral atrophic macular lesions consistent with STGD4. Targeted exome sequencing of known inherited retinal degeneration genes revealed a heterozygous missense mutation c.1117C>T (p.R373C) of PROM1, which was confirmed by Sanger sequencing. To the best of our knowledge, this is the first case of a PROM1 mutation causing STGD4 in Koreans.