SCN8A and movement disorder: Among DEE-related mutated genes listed in the OMIM database, tremor as a movement disorder is relatively rare, and involves multiple pathways, including ion channels (e.g., CACNA1A, KCNQ2, SCN2A, SCN8A, SCN1A), enzymes/regulatory proteins (e.g., CDKL5, CHD2, UGDH, DNM1), membrane transport regulation (e.g., NAPB, STXBP1), nucleic acid-binding proteins (e.g., CELF2), and cellular metabolism and signal transduction (e.g., YWHAG) [8, 10, 11, 26, 29].