KCNE2. A gene on chromosome 21q22.12 that encodes a member of the voltage-gated, isk-related potassium channel subfamily; it is a small-membrane subunit, which assembles with the KCNH2 protein product, a pore-forming protein, and is expressed in heart and muscle.Molecular pathology.CNE2. A gene on chromosome 21q22.12 that encodes a member of the voltage-gated, isk-related potassium channel subfamily; it is a small-membrane subunit, which assembles with the KCNH2 protein product, a pore-forming protein, and is expressed in heart and muscle. Molecular pathology.