Electron microscope image showing an amyloid plaque and tau fibres (dark pink lines) in the brain of a person with Alzheimer’s disease. Amyloid plaques are insoluble aggregates of beta-amyloid protein.Credit: Thomas Deerink/NCIR/SPL
Researchers have identified a man with a rare genetic mutation that protected him from developing dementia at an early age. The finding, published on 15 May in Nature Medicine1, could help researchers to better understand the causes of Alzheimer’s disease and potentially lead to new treatments.
For nearly 40 years, neurologist Francisco Lopera at the University of Antioquia in Medellín, Colombia, has been following an extended family whose members develop Alzheimer’s in their forties or earlier. Many of the approximately 6,000 family members carry a genetic variant called the paisa mutation that inevitably leads to early-onset dementia. But now, Lopera and his collaborators have identified a family member with a second genetic mutation — one that protected him from dementia until age 67.
“Reading that paper made the hair on my arms stand up,” says neuroscientist Catherine Kaczorowski at the University of Michigan in Ann Arbor. “It’s just such an important new avenue to pursue new therapies for Alzheimer’s disease.”
Mutated protein
Lopera and his colleagues analysed the genomes and medical histories of 1,200 Colombians with the paisa mutation, which causes dementia around ages 45—50. They identified the man with the second mutation when he was 67 and had only mild cognitive impairment.
When the researchers scanned his brain, they found high levels of the sticky protein complexes known as amyloid plaques, which are th
