KCNQ genes encode members of the KV7 K+ channels. Structurally, the KCNQ family belongs to the six transmembrane domain category of K+ channels. Five members belong to this family (KCNQ1-KCNQ5) of which KCNQ2 to KCNQ5 are expressed in the nervous system. KCNQ5 is also expressed in visceral smooth muscle and skeletal muscle.
These channels form subunits of the low threshold voltage-gated K+ channel. KCNQ2 and KCNQ3 mostly form heteromers to form the M current. KCNQ5 is known to contribute to this current.