Table 1. Overview of all KCNQ4 mutations identified to date.

Mutation DNA	Protein	Exon	Origin	reference
c.211_223del13	p.Q71fs	1	Belguim	Coucke et al. (1999)
c.211delC	p.Q71fs	1	Japan	Kamada et al. (2006)
c.229_230insGC	P.H77fs	1	Japan	Naito, et al. (2013)
c.546C>G	p.F182L	4	Taiwan,	Su, et al. (2007);
			Japan	Naito, et al. (2013)
c.664_681del18	p.G215_220del6	4	Korea	Beak, et al. (2010)
c.689T>A	p.V230E	4	Japan	Naito, et al. (2013)
c.725G>A	p.W241X	5	USA	Hildebrand, et al. (2008)
c.778G>A	p.E260K	5	USA	Hildebrand, et al. (2008)
c.785A>T	p.D262V	5	USA	Hildebrand, et al. (2008)
c.821T>A	p.L274H	5	Neth	Van Hauwe, et al. (2000); De Heer, et al. (2011)
c.823T>C	p.W275S	5	China	Present study
c.827G>C	p.W276S	5	Neth, Japan	Coucke et al. (1999), Akita et al. (2001), Camp, et al. (2002), Topsakal, et al. (2005)
c.842T>C	p.L281S	6	USA	Talebizadeh, ea al. (1999)
c.853G>T	p.G285C	6	USA	Coucke et al. (1999)
c.853G>A	p.G285S	6	France,	Kubisch, et al. (1999)
			China	Present study
c.859G>C	p.G287R	6	USA	Arnett, et al. (2011)
c.871C>T	p.P291S	6	Japan	Naito, et al. (2013)
c.872C>T	p.P291L	6	Japan	Naito, et al. (2013)
c.886G>A	p.G296S	6	Spain	Mencia, et al. (2008)
c.891G>T	p.R297S	6	Japan	Naito, et al. (2013)
c.961G>A	p.G321S	7	Neth	Coucke et al. (1999)