Dominant de novo missense variants in KCNH1 (MIM: 603305), encoding the Eag1 (Kv10.1) channel belonging to the ether-à-go-go family of voltage-gated K+ channels, have not only been identified in subjects with ZLS [14], but also in subjects with Temple–Baraitser syndrome (TBS; MIM: 611816) [15]. Here, KCNH1 is linked to Townes-Brocks syndrome.