K_ir7.1 (KCNJ13) is a member of the inward rectifying K⁺ channel family. The family includes 15 members that are structurally and functionally different from the voltage-dependent K⁺ channels.

The family’s protein topology consists of two transmembrane domains that flank a single and highly conserved pore region with intracellular N- and C-termini. As is the case for the voltage-dependent K⁺ channels, the functional unit for the K_ir channels is composed of four subunits that can assemble as either homo- or heteromers.

K_ir channels are characterized by a K⁺ efflux that is limited by depolarizing membrane potentials thus making them essential for controlling resting membrane potential and K⁺ homeostasis¹.

K_ir7.1, an inwardly rectifying K⁺ channel with unusual permeation properties is localized in epithelial cells of the thyroid, small intestine, kidney tubules, choroid plexus and in retinal pigment epithelium (RPE), where it forms a major component of the apical membrane K⁺ conductance².

A mutation in the gene encoding the channel was found to cause snowflake vitreoretinal degeneration (SVD) which is a developmental and progressive hereditary eye disorder that affects multiple tissues within the eye³.