SCN4A and congenital myasthenic syndrome: Mild to severe cognitive impairment has been reported in patients carrying mutations in the SLC5A7 gene, DPAGT1 gene [124], SNAP25 gene [30], COL13A1 gene [52], MYO9A gene [86], MUNC13–1 gene, and in SCN4A-related CMS [20, 96].