Future studies deciphering the role of SLC66A1 in the retina, as well as the functional consequences of absent SLC66A1 in patient cells and model systems are needed to definitively establish the gene-disease association,20 although the 4 families presented here and the 2 families described previously4 strongly suggest a causal relationship with inherited retinal disease. The gene discussed is SLC66A1; the disease is Abnormal retinal morphology.