The transition temperature of erythrocyte ghosts of normal subjects is about 18-20 degrees C. We have studied the viscosity of erythrocyte ghosts of dystrophic children, showing that the transition shifts to lower temperatures (17-18 degrees C). After treatment with erythrocytic compounds like L-Lyso phosphatidyl-Choline dystrophic erythrocytes hemolize at lower Lysophosphatidyl-Choline concentration and at a greater extents than these of normal and carriers subjects.