Neuropathological lesions in SACD have been found to be due to overproduction of the myelinolytic Tumor necrosis factor α (TNFα) and to the reduced synthesis of the two neurotrophic agents; the Epidermal growth factor (EGF) and interleukin-6 caused by vitamin B12 deficiency [8]. The gene discussed is EGF; the disease is vitamin B12 deficiency.