Of the 4 young children tested using periorbital skin electrodes, noisy ERG recordings in the youngest (aged 4 years) were equivocal; in the others (aged 5, 5, and 10 years) the ERGs showed features consistent with KCNV2-associated retinopathy (Supplemental Figure 2). The gene discussed is KCNV2; the disease is retinal disorder.