Development of a rapid functional assay that predicts GLUT1 disease severity by Zaman, SM, Mullen, SA, Petrovski, S, Maljevic, S, Gazina, EV, Phillips, AM, Jones, GD, Hildebrand, MS, Damiano, J, Auvin, S, Lerche, H, Weber, YG, Berkovic, SF, Scheffer, IE, Reid, CA, Petrou, S