KCNJ9 and migraine disorder: Results showed no significant difference between controls and migraine patients for the allelic frequencies (χ2 = 1.59, 2 df, P = 0.207; χ2 = 0.46, 2 df, P = 0.713; χ2 = 1.06, 2 df, P = 0.496; χ2 = 0.14, 2 df, P = 0.303; χ2 = 1.00, 2 df, P = 0.6 respectively for ATP1A4, CASQ1, KCNJ9, KCNJ10 and CACNA1E).