The unusually high incidence of early-onset Alzheimer’s disease in this isolated cattle town has thrust it to the forefront of global efforts to find a cure for the debilitating malady. Next spring, 100 residents of this region in northwestern Colombia who are known to carry a mutant gene linked to the disease will begin taking a therapeutic drug produced by the U.S. biotechnology firm Genentech. The five-year clinical trial, called the Alzheimer’s Prevention Initiative, will cost $100 million. The effort is backed by the U.S. National Institutes of Health and includes UCLA. What sets this drug trial apart is that the patients, most of them in their 30s, will begin treatment long before they show symptoms of Alzheimer’s. Researchers hope the drug will prevent its onset by blocking or slowing the formation of amyloid plaques in the brain that are associated with the devastating illness. Because of a rare genetic predisposition among interrelated families, scores of residents here and in surrounding towns are getting Alzheimer’s by their late 40s, about 15 years ahead of the norm. The cases can be traced to a “founder effect": a common ancestor’s “misspelled” gene, passed down over generations, that makes developing Alzheimer’s a virtual certainty. “It’s a heavy burden for the relatives when the victims have to stop working and raising their children at such an early age,” said Carlos Orrego, administrator at San Juan de Dios Hospital, Yarumal’s biggest. “For the families, the burden can last a very long time.” But the tragic circumstances also make this community an ideal place to test the Genentech drug, called crenezumab, which attacks beta amyloids and prevents them from becoming toxic.
