In the case of SVD, depolarization of the RPE membranes as shown by co-expression of wild-type and mutant Kir7.1 channels could affect the photoreceptor-RPE interaction and compromise the integrity of the epithelial barrier thereby contributing to the snowflake-like depositions that are ultimately associated with RPE degeneration. The gene discussed is KCNJ13; the disease is snowflake vitreoretinal degeneration.