<qa>  How many people with Down syndrome have been recruited at approximately 21 trial sites?The goal of this international three-year study is to determine whether the administration of vitamin E, which has been shown to delay the progression of Alzheimers disease, will slow the rate of cognitivefunctional decline in persons age 50 or older with Down syndrome. Persons with Down syndrome functioning at all levels of intellectual disability will be eligible. Men and women of approximately equal numbers and people from minorities and ethnic groups other than Caucasian will be included. A total of 350 individuals with Down syndrome, 50 years of age and older, have been recruited at approximately 21 trial sites. The study is a randomized, double-blind, placebo-controlled, parallel group design with stratification by geographic site and presence of Alzheimer disease according to DSM-IV American Psychiatric Association criteria for diagnosing this disease. 