Stargardt Disease Due to an Intronic Mutation in the ABCA4: A Case Report

PURPOSE: To report on a patient with Stargardt disease (STGD1) and with an intronic mutation in the ABCA4 gene. PATIENTS AND METHODS: A 69-year-old female patient presented to the clinic complaining of progressive vision loss. The ophthalmic evaluation was remarkable for a best corrected visual acuity of counting fingers at 5’ in the right eye and 3’ in the left eye. Imaging revealed deep extensive atrophy of the central macula, epithelial pigment hyperplasia, and other areas of multifocal atrophy in the right eye. Furthermore, fundus autofluorescence imaging of the macula showed central hypoautofluorescence with bilateral expansion to the periphery in both eyes. A full-field electroretinogram showed a normal rod response, with decreased cone response, bilaterally. Genetic testing was positive for a homozygous intronic mutation in the ABCA4 gene of the variant c.5714+5G>A. CONCLUSIONS AND IMPORTANCE: Patients with STGD1 due to presumed mild or moderate mutations in the ABCA4 gene may have a more severe presentation and progression of the disease. Based on this, the first report of a genotype–phenotype correlation in a Puerto Rican patient with STGD1 disease, genotyping all Puerto Rican patients is warranted.