Usami et al. reported that the frequent responsible genes for juvenile-onset HL were KCNQ4, Mitochondria m.3243A>G variant and m.1555A>G variant, CHD23, MYO6, MYO7A, ACTG1, POU4F3, and WFS1 [9]. The gene discussed is KCNQ4; the disease is Onset.