KCNJ13 and snowflake vitreoretinal degeneration: It appears that the autosomal dominant inheritance pattern of SVD due to the Kir7.1 R162W mutation probably results from depolarization of the resting membrane potential of the RPE by the mutant protein, perhaps exacerbated by insertion of R162W mutant Kir7.1 molecules into the tetrameric Kir7.1 channels in a partial dominant negative effect (Hejtmancik et al., 2008; Pattnaik et al., 2013; Zhang et al., 2013); while the autosomal recessive LCA phenotype results from a complete loss of channel function (Sergouniotis et al., 2011; Pattnaik et al., 2015; Perez-Roustit et al., 2017).