The Alzheimer's Prevention Initiative (API) is a collaborative research program involving the Neurosciences Group of Antioquia (GNA), Genentech, the Banner Alzheimer's Institute (BAI) and key partners that evaluates promising treatments with the ultimate goal to postpone, reduce the risk of, or prevent the clinical onset of Alzheimer's disease (AD). The Colombian API Registry is created and conducted by the GNA/University de Antioquia. The main goal is to register E280A (PS1) family members in Colombia (including kids over 8 years old) and to perform medical and cognitive evaluations. The Colombian API Registry provides a resource for enrollment into the API Colombia clinical trial and for biomarker and cognitive studies of Autosomal Dominant Alzheimer's Disease (ADAD). The Colombian Registry was formally launched as the API Registry in 2010 and expanded in 2014. To search for new members and new E280A families in Colombia, GNA has used a variety of strategies including: sending letters to medical professionals, organizing press conferences for national and international media, meeting with universities, giving awareness talks/conferences/lectures, making town visits, reviewing existing E280A pedigrees and contacting missing family members. The team created advertisements and a website, participated in media activities (radio, TV and newspapers), and filmed a documentary. GNA promotes a social network/digital media campaign including a collaboration with Lumos Labs. All Registrants have medical and neuropsychological evaluations and are tested for the PSEN1 E280A mutation. The Registry currently includes >4,700 living members from 25 families in the PSEN1 E280A kindred, including 4 new families that were identified in 2015. Kindred members, 8 to 61 years of age, include >1,000 living mutation carriers (23% of the kindred) and the first 6 persons documented to be homozygous for an ADAD. The most effective strategy to find new family members has been the pedigree review and the most effective strategy to find new E280A families are the TV advertisements. In parallel, GNA found and described other families with AD caused by different mutations. The Colombian API Registry provides an exceptionally large and growing ADAD resource for API trials, preclinical AD trials, and other studies of AD.