Down Syndrome and Alzheimer's Disease Contrasted

All adults with Down syndrome above the age of 30 or 35 are believed to have the neuropathologic and biochemical changes diagnostic of Alzheimer's disease. During the past 35- 40 years, hundreds of patients with Down syndrome and patients with several other disorders associated with mental retardation, but not dementia, have been treated at the Turkel Clinic with the "U " Series (Fig. 1, pre-1984 and European formulation of the "U " Series; Fig. 2, U.S. formulation of the "U " Series), and thousands more have been treated in other countries. Some of these patients are now in their 40s and 50s; they have not developed Alzheimer's disease. Alzheimer's disease and Down syndrome have been linked in the lay and professional press because of comparable structural and chemical alterations of the brain, and dermatoglyphic similarities. Although the gene that causes Alzheimer's disease is located on chromosome 21, the presumed excess of Down syndrome cases in families with familial Alzheimer's disease has not been cor-roborated by a three-year investigation by th