1.A.1.2.17
Potassium voltage-gated channel (KCNH) subfamily G member 3 (Voltage-gated potassium channel subunit Kv10.1) (Voltage-gated potassium channel subunit Kv6.3).  Splice variants have different properties and can activate cyclin-dependent protein kinases (Ramos Gomes et al. 2015). Control of transport (pore) function  by the voltage sensor may involve more than one mechanism (Tomczak et al. 2017).  The silent (non transporting) behaviour of Kv6.3 in the ER is caused by the C-terminal part of its sixth transmembrane domain that causes ER retention (Ottschytsch et al. 2005).  De novo missense variants in KCNH1 encoding Kv10.1 are responsible for two clinically recognisable phenotypes: Temple-Baraitser syndrome (TBS) and Zimmermann-Laband syndrome (ZLS) (Aubert Mucca et al. 2022). The clinical overlap between these two syndromes suggests that they belong to a spectrum of KCNH1-related encephalopathies. Affected patients have severe intellectual disability (ID) with or without epilepsy, hypertrichosis and distinctive features such as gingival hyperplasia and nail hypoplasia/aplasia (Aubert Mucca et al. 2022).