Are We Betting on Alzheimer’s 'Protective' Genes? Christchurch Mutation Investigation Raises Troubling Questions

Medellín, Colombia, MMN Correspondent: For years, the story of Aliria Rosa Piedrahita de Villegas carried a rare kind of hope. She came from a family where Alzheimer's tended to strike in middle age, and she stayed mentally sharp well into her 70s. Scientists pointed to a single genetic variation, the Christchurch mutation, as the reason. The idea was elegant: one tiny change in a gene, and the brain might be protected from a devastating disease. A new investigation by Science magazine now invites us to slow down and ask whether that idea could withstand closer inspection.

The investigation looks closely at the evidence behind this genetic story. It focuses on whether the specific claims about the Christchurch mutation and related variants hold up when examined carefully. What emerged is a layered picture with unanswered questions about data, images, and the role of hope in scientific interpretation.

The family at the center of this story lives in Antioquia, Colombia. Thousands of its members carry the 'paisa' mutation in the PSEN1 gene, a change that usually causes Alzheimer's in middle age. The late neurologist Francisco Lopera and his team at the Neuroscience Group of Antioquia spent decades caring for them and learning from them. In 2019, a group led by Joseph Arboleda-Velasquez and Yakeel Quiroz announced that Aliria carried two copies of the Christchurch variant on her APOE3 gene. They proposed that this variant protected her. The study made headlines and raised expectations for a new wave of therapies.

More findings followed. In 2023, the same team described a second mutation, Reelin-COLBOS, in another paisa carrier. In 2024, a paper in The New England Journal of Medicine reported that even one copy of the Christchurch mutation could delay the onset of Alzheimer's by roughly five years. Each new announcement seemed to bring a therapy closer. Startups formed, labs shifted focus, and a human gene therapy trial began.

That promise now faces serious questions. Science magazine's investigation reviewed more than 1,000 documents, including emails, patents, and grant applications, and interviewed dozens of independent experts. Forensic image analysts found what they describe as duplicated or altered images in three key papers. These included the first description of Reelin-COLBOS and laboratory studies on Christchurch's effects. Independent scientists who studied the images said the duplications were clear and had a direct bearing on the reported results.

The clinical data also drew scrutiny. The 2024 NEJM paper relied on a reassessment of 353 paisa carriers. When scientists compared the new ages of onset with earlier data, several Christchurch carriers had been shifted to later ages. One patient's age at mild cognitive impairment changed from 42 to 52. A clinician who reviewed the original file found nothing that would explain such a dramatic revision.

The research team addressed the changes. Quiroz explained that hundreds of cases were reopened and a consensus of clinicians corrected inconsistencies. A clinician who participated in those reviews offered a different account. According to this clinician, the committee advised against changing most ages. The two researchers who supplied the case lists were Arboleda-Velasquez and Quiroz, and they were not blinded to which patients carried the protective variant. That detail raises questions among independent researchers. When people interpreting data know which group a patient belongs to, even subtle choices can influence the outcome. The result is not necessarily intentional. It is human nature.

A similar dynamic surrounds a third mutation called Macondo, named after the fictional town in Gabriel García Márquez's novel. Two scientists who initially worked on the paper withdrew their names after reanalyzing the data. Diego Sepulveda-Falla and Kenneth Kosik found that some paisa carriers with the Macondo mutation developed dementia at very different ages. They concluded that the mutation was not a reliable shield on its own. Their decision to step back is science working as it should.

The stakes extend beyond journal pages. A human gene therapy trial at Weill Cornell Medicine and a startup co-founded by Arboleda-Velasquez are built around the Christchurch mutation. If the genetic evidence weakens, those efforts will need a new foundation. The biology may still turn out to be useful. Laboratory studies suggest the mutation can influence tau proteins and amyloid under certain conditions. Those observations might still guide future work. What changes is the level of certainty.

For families touched by Alzheimer's, hope remains. It can and should be paired with a demand for stronger evidence. Science has a way of testing our patience. A promising clue can take years to confirm, revise, or let go. The families who carry the paisa mutation continue to contribute in profound ways. Their participation has already taught the world more about Alzheimer's than any single experiment. The hope now is that this investigation will lead to more transparency, better safeguards, and a clearer path forward.