Runhart EH, Khan M, Cornelis SS, et al. - In this cross-sectional study involving 550 patients [mean (SD) age was 45.7 (18.0) years and most patients were women (311 {57%})], researchers sought to evaluate the correlation of incompletely penetrant ABCA4 alleles with gender in Stargardt disease (STGD1). This investigation found a difference in the observed gender ratio among patients harboring a mild ABCA4 allele, which concerns nearly 25% of all patients with STGD1, indicating that STGD1 should be considered a polygenic or multifactorial disease rather than a disease caused by ABCA4 gene mutations alone. In both basic research and clinical trials on STGD1, gender should be considered as a potential disease-modifying variable.