ABCA4 and severe early-childhood-onset retinal dystrophy: Stargardt disease (STGD) (Mendelian Inheritance in Man identifier, #248200) is the most common inherited retinal dystrophy worldwide, with an estimated prevalence of 1 in 6578 individuals.1, 2, 3 Stargardt disease was first described more than a century ago and occurs as a result of biallelic disease-causing variants in ABCA4, with > 1500 pathogenic variants reported to date.4