This gene encodes a member of the monovalent cation:proton antiporter 2 (CPA2) family of transporter proteins. Members of this family typically couple the export of monovalent cations, such as potassium or sodium, to the import of protons across cellular membranes. Mutations in this gene have been identified in patients with a rare inherited vision defect, cornea guttata with anterior polar cataract. [provided by RefSeq, Mar 2017].