Both Alzheimer's disease and DM are linked with decreased insulin secretion, reduced uptake of glucose, raised oxidative stress, angiopathy, activation of the apoptotic pathway, aging, abnormal peroxidation of lipids, increased production of advanced glycation end products and tau phosphorylation, brain atrophy, and decreased fat metabolism. The gene discussed is MAPT; the disease is early-onset autosomal dominant Alzheimer disease.