Protein reelin may delay Alzheimer's onset by about 20 years

Researchers report a reelin-related gene variant called COLBOS delayed Alzheimer's symptoms by roughly 20 years in a person with a high-risk PSEN1 mutation, and a December 2025 study mapped how COLBOS strengthens reelin binding to heparan sulfate at neuron surfaces.

Researchers describe a single gene variant, dubbed COLBOS, that substantially delayed the onset of Alzheimer’s symptoms in a person who carried a highly penetrant PSEN1 mutation. Background work by clinicians in Colombia identified the family affected by the PSEN1 mutation, and later studies linked the resilient case to the COLBOS variant. A December 2025 paper in the Journal of the American Chemical Society reported laboratory measurements showing how COLBOS changes reelin behavior at neuron surfaces. The authors and other scientists view the finding as a step toward understanding protective mechanisms in Alzheimer’s disease. Key findings: - The COLBOS variant was associated with roughly a 20-year delay in clinical onset for a person with a PSEN1 early-onset Alzheimer’s mutation, as reported in prior clinical work. - Laboratory experiments in the December 2025 study showed COLBOS strengthens binding between the signaling protein reelin and the cell-surface sugar heparan sulfate, promoting reelin localization at neuron surfaces. - Reelin signaling is reported to slow processes linked to Alzheimer’s pathology, including tau phosphorylation and amyloid accumulation, and the COLBOS change appears to enhance those effects. - The researchers emphasize COLBOS appears to delay but not prevent disease in the presence of the PSEN1 mutation, and they are exploring ways to translate the mechanism into therapies, including discussions about a gene-therapy approach. Summary: The study clarifies a possible molecular mechanism by which the COLBOS variant made reelin more effective at neuron surfaces, which correlated with a long delay in symptom onset for one high-risk individual. Researchers say the mechanism suggests directions for therapeutic research, and investigators are discussing gene-based strategies to enhance reelin signaling; broader clinical implications remain under study.