ABCA4-associated retinal degeneration (ABCA4-RD) encompasses a wide phenotypic spectrum that can make diagnoses difficult, according to findings published in Diagnostics. Beau Fenner, MD, and colleagues examined the phenotypic diversity of ABCA4-RD through a series of representative cases compared with conditions that closely mirror ABCA4-RD. Phenotypes in the series included typical adolescent-onset Stargardt disease with flecks, bull’s eye maculopathy without flecks, fundus flavimaculatus, late-onset Stargardt disease, and severe early-onset Stargardt disease. Phenocopies of ABCA4-RD included macular dystrophy, cone dystrophy, advanced retinitis pigmentosa, and Leber congenital amaurosis, among others. Characteristics often suggestive of ABCA4-RD include the presence of peripapillary sparing, macular involvement and centrifugal distribution, and a recessive history. The study authors noted that these features, either in isolation or in combination, should serve as an indicator for clinicians to suspect ABCA4-RD. “Awareness of the clinical spectrum of disease can facilitate prompt recognition and accurate diagnostic testing,” Dr. Fenner and colleagues wrote.