KCNJ2 and channelopathy: Genes associated with channelopathies (SCN4A, CACNA1S, KCNJ2, CLCN1) or congenital myasthenic syndrome and related disorders (CHRNA1, CHRNB1, CHRND, CHRNE, RAPSN, CHAT, MUSK, COLQ, DOK7, AGRN, GFPT1, DPAGT1, LAMB2, CHRNG, PLEC) were specifically checked.