Scientists at the University of California have identified a previously unknown gene variant that appears to raise the likelihood of developing Alzheimer’s disease before age 65. The finding adds to growing evidence that genetics can play a major role in how and when the brain disorder develops.

According to the researchers, the variant was linked to a significantly higher risk of early-onset cases, which affect patients in midlife rather than in older age. Early-onset Alzheimer’s is less common than late-onset forms, but it can be especially devastating because it often strikes people who are still working and raising families.

The discovery may help improve screening and deepen understanding of the biological pathways behind the disease. While a single gene variant does not determine whether someone will develop Alzheimer’s, studies like this can help scientists identify people at higher risk and guide future treatments.

Researchers say more work is needed to confirm how the variant affects brain function and whether it could become a target for new therapies. For now, the finding is another step toward earlier detection and a clearer picture of the disease’s causes.