Scientists have discovered a gene that almost doubles the risk of developing the most common form of dementia, Alzheimer’s disease. This gene may be the new target for developing new treatments for Alzheimer’s, which affects one in 20 of those over 65, causing loss of memory, personality changes, and eventually death.

According to the World Health Organization, there are about 18 million people with Alzheimer’s, worldwide. Existing drugs can only ease the symptoms of the disease and not cure it. If this situation maintains, the WHO estimates the number of people with Alzheimer’s will almost double by 2025, reaching 34 million.

Dr. Philippe Marambaud of the Feinstein Institute for Medical Research and Albert Einstein College of Medicine and Dr. Fabien Campagne of the Weill Medical College of Cornell University, lead authors of the study and their colleagues say the gene appears to restrict a brain cell’s ability to take in calcium.

Until now, only one gene had been identified as a likely culprit –ApoE4. This gene occurs in about 40 percent of patients who develop Alzheimer’s after the age of 65, according to statistics of the National Institute on Aging.

The new study reveals that variations of the gene, known ad CALHM1, controls the flow of calcium in and out of cells, thus influencing the formation of plaques composed of clumps of a protein called beta-amyloid, thought to damage brain cells in the disease.

“We have strong evidence that, by manipulating calcium levels, you can also impact amyloid levels,” Dr. Marambaud said, according to the San Francisco Chronicle.

Therefore, scientists are ready to test whether drugs will disrupt the effects of this gene. However, it might take another 10 years to develop a drug, which could fight Alzheimer’s by targeting this gene, Dr. Marambaud added.

CALHM1, like ApoE4 is thought to play an important “piece to the puzzle” of the genetics of Alzheimer’s disease.  

However, Dr. Marambaud warns that a “reliable diagnostic will only be possible when all the genetic risk factors and the complex interplay will be defined. This new work, however, provides a better understanding of the pathogenic mechanisms leading to Alzheimer’s disease and clearly identifies CALHM1 as a potentially important new molecular target for therapy.”

The study and its findings are published in the June 27 issue of the journal Cell.