Researchers uncovered a gene variant unique to Japanese that increases by sixfold the risk of Alzheimer's disease.

Although this variant is found only among 0.1 percent of all Alzheimer's patients, the scientists expect that the finding will shed light on the disease's mechanism and open the door for new treatments.

The team, comprising members of the National Center for Geriatrics and Gerontology in Obu, Aichi Prefecture, and other entities, announced the finding on June 20.

The researchers analyzed the genomes of about 200 late-onset Alzheimer's disease patients who lack APOE4 genes, known as a factor that increases the risk of Alzheimer's.

Based on differences among 500,000 individual DNA arrangement variations, the team narrowed down seven as candidate risk variants.

It then analyzed the genes of about 4,500 Alzheimer's patients and those of about 16,000 people who do not suffer from the disease.

The team discovered that a rare "Sharpin" variant increased a person's likelihood of developing the disease by 6.1 times compared to those without the variant.

“Detailed research on how this gene works could illuminate the mechanism of the disease's development that is not still known," said Koichi Ozaki, director of the division promoting analysis of clinical genomics at the center.

"This could lead to the development of new medical treatments from a non-traditional approach."

The study was published on June 20 in Molecular Medicine, a U.S. science journal.

It is available at (https://molmed.biomedcentral.com/articles/10.1186/s10020-019-0090-5).