History of a curse

1750: Maria Luisa, believed to be the first paisa mutation carrier, is born in Antioquia. She and her husband, Javier, are descendants of European settlers. They have at least three children.

1750s to 1980s: For more than two centuries, the mutation is passed from generation to generation in the genetically isolated northwestern province.

1984: Dr. Francisco Lopera diagnoses Pedro Julio with hereditary early-onset Alzheimer’s disease and the genealogical detective work begins.

1995: Together with Dr. Kenneth Kosik, then at Harvard Medical School, and Alison Goate from Washington University, Lopera identifies the exact location of the paisa mutation on chromosome14.

Late 1990s: Lucia Madrigal, psychologist and nurse, is kidnapped by guerillas while collecting blood samples in Dabei-ba, a town north of Medellin. She demands they take care of the samples, so the fighters chill them in a lake until they release her several days later. Violence keeps researchers from going back regularly for several years.

2000s: Twenty-five mutation-carrying families have been identified. Lopera has proved that roughly half are descendants of Maria Luisa and Javier. He believes the other families are descendants but incomplete birth records make it impossible to prove.

2012: Plans for a clinical trial are announced.

2013: The research team administers the drug to the first study participants in December.

2015: Recruitment continues. The research team hopes to have all 300 participants by December. The trial will end five years after the final volunteer receives his or her first injection. Amy Dempsey