To help advance the study of early-onset autosomal dominant Alzheimer's disease (ADAD), we have created a registry of people in families affected with ADAD caused by the PSEN 1 E280A mutation. This registry builds upon our efforts of nearly 20 years to establish a database of contact information about affected families in the region of Antioquia, Colombia. It will facilitate enrollment into the Alzheimer's Prevention Initiative's (API) preclinical treatment trial of crenezumab in the world's largest ADAD kindred. The registry aims to enroll 3,300 participants by the end of 2013, including close to 1,000 mutation carriers. Members of the PSEN 1 E280A mutation kindred, are invited to join the registry. After consent, individuals provide a clinical history and undergo physical examinations, neuropsychological testing, and genotyping for the PS1 mutation. Between February 2010 and December 2012, 2,092 individuals were enrolled and 2,081 genotyped. Of those genotyped, 597 (29%) are mutation carriers. 40% of enrollees have some level in primary education, 46% have some level of secondary education and 14% have some level of higher education. 331 carriers (55.5%) were asymptomatic, 55 (9%) were asymptomatic pre-MCI, 9 (1.5%) had pre-symptomatic MCI, 101 (17%) had MCI and 101 (17%) have dementia according to our classification criteria (Acosta et al, 2011). Of the 395 mutation carriers without MCI or dementia, 182 are in the 28–60 year-old age range to be considered for our pending clinical trial. The place of residence of this subgroup is distributed as follows: 54% live in or near Medellin, 28% live in or near Yarumal and 18% live in more distant cities in Colombia. Of the 182 candidates 167 (92%) would like to participate in the clinical trial, 6 (3.5%) did not wish to do so, 6 (3.5%) have doubts and 2 (1%) have not decided. The registry has been well-received by the affected ADAD families. We are on target for meeting our enrollment goal of 3,300 people. This registry will serve as a resource for other ADAD studies in Colombia.