Gene therapy for Stargardt Disease

An inherited macular degeneration called Stargardt disease is often symptomatic in childhood and young adulthood. Degeneration of macular cells causes loss of central vision and thus fine visual discrimination (the ability to read, recognize faces) and impairs color vision. Stargardt disease is caused by autosomal recessive mutations in a gene called ATPase Binding Cassette Retina (ABCR, ABCA4). ABCA4 mutations can also result in related conditions such as cone-rod dystrophy, fundus flavimaculatus and may contribute to disease in some forms of age-related macular degeneration. Like LCA-CEP290, the ABCA4 gene is large and surpasses the limited cargo capacity of recombinant adeno-associated virus (AAV vectors). Our team is testing alternative approaches for delivering the wild type ABCA4 cDNA to photoreceptors both in vitro and in vivo. Concurrent with development of a gene-based approach for treating Stargardt disease (and/or cone-rod dystrophy), non-invasive studies in progress aim to characterize genotype:phenotype relationships in patients with this condition.