['In this report are reviewed two unrelated patients with typical normokalemic periodic paralysis (normoKPP) features and the results of screening the SCN4A gene for the disease-related mutation.', 'Two sporadic cases with normoKPP were screened for previously known mutations in SCN4A gene (T704M, A1156T, M1360V, I1495F, M1592V) that lead to hyperKPP; denaturing high performance liquid chromatography (DHPLC) was used. Then the rest exons of SCN4A gene were screened by DHPLC, and sequence analysis was performed on those with DHPLC chromatogram variation when compared with unaffected control.', "Two cases and one patient's father were detected with V781I, which was proved to be a singular missense mutation in SCN4A gene."] Does [ The mutation V781I in SCN4A gene exist in Chinese patients with normokalemic periodic paralysis ]?