Scientists have found a protein in the brain that’s linked to early-onset dementia and could also play a role in motor neuron disease. 

Dementia, along with other neurodegenerative disorders, involve proteins grouping together into filaments called amyloids. Scientists have largely pinpointed which proteins tend to clump together, but they haven’t found which proteins are to blame for about 10% cases of frontotemporal dementia. 

In a report in Nature on Dec. 6, researchers call out the TAF15 protein as the likely culprit, and encourage more research into TAF15.

Frontotemporal dementia typically shows up earlier than Alzheimer’s disease. It’s diagnosed in people between 45 and 65, though it can pop up in people older and younger. 

The scientists say that the identification of the TAF15 protein could be the focal point for future diagnostic techniques and technology, as well as treatments. The team used advanced cryo-electron microscopy (cryo-EM) to look at the protein aggregates in the brains of four people with frontotemporal dementia, which is how they spotted TAF15 in groups.

The researchers showed that the protein clumps found in each brain had an identical atomic structure to each other. Scientists formerly thought the FUS protein was to blame until they spotted TAF15. TAF15 hasn’t been named for its role in forming amyloid filaments in neurodegenerative conditions, and there weren’t details about its structural characteristics until now. The report could be a jumping-off point for more research into how TAF15 behaves, and how treatments could stop it from forming into clumps.

The team also found the same aggregated TAF15 protein in the brains of two people who donated their brains for the study and had frontotemporal dementia along with motor neuron disease. People with motor neuron disease have progressive muscle control loss. The authors said the presence of TAF15 aggregates mean that the proteins may contribute to both ailments. Researchers want to see if the abnormal TAF15 aggregates exist in people with motor neuron disease who do not have frontotemporal dementia.