SCN8A and Tremor: The identified genes were GNAO1, SCN8A, CACNA1A, SCN1A, WWOX, CDKL5, SCN2A, KCNQ2, STXBP1, and KCNA2. The spectrum of movement disorders include involuntary movements, dystonia, ataxia, chorea, myoclonus, tremors, spasms, and central motor disorders.