ABCA4 and severe early-childhood-onset retinal dystrophy: There were 12 patients with rod-cone dystrophy (RCD) caused by pathogenic variants in eight different genes (Table 1), three patients with STGD caused by two pathogenic variants in the ABCA4 and two patients with Best disease caused by at least one pathogenic variant in the BEST1. Four eyes of patients with IRD were excluded because they did not meet visual acuity criteria.