Until now, only a small number of CMT families with GNB4 mutations, including two Han Chinese (p.Gly53Asp and p.Lys89Glu), one Czech (p.Lys57Glu), and one Japanese family (p.Gln220Arg), have been reported [13,14,15]. The gene discussed is GNB4; the disease is Charcot-Marie-Tooth disease.