麻豆传媒

A rare mutation of a gene that鈥檚 normally linked to inflammation could triple the risk of Alzheimer鈥檚 disease, according to new research from an international team of scientists.

Less than 1 per cent of the population has the gene variant, called TREM2. Scientists hope that by studying the gene they will better understand how Alzheimer鈥檚 attacks the brain -- and find a way to stop it.

Their findings were published Wednesday in the New England Journal of Medicine.

About 30 million people around the world have Alzheimer鈥檚, and that number is expected to rise to 35 million in the next three years.

The incurable disease first destroys the mind鈥檚 ability to remember. Over time, as brain cells are attacked, symptoms worsen and patients lose more of their mental abilities until they are entirely dependent on caregivers.

Until now, it鈥檚 been commonly thought that the disease is caused by Amyloid plaques -- a sticky, toxic material. Based on this theory, pharmaceutical companies have spent hundreds of millions of dollars testing medications to treat Alzheimer鈥檚, but most attempts have failed clinical studies.

The new research suggests those experimental treatments were pointed in the wrong direction, and that TREM2鈥檚 role suggests inflammation could be the main culprit.

鈥淲hat we are now finding out from genetic study is that inflammation is an important part of the disease itself,鈥� Dr. Peter St. George-Hyslop of the University of Toronto told 麻豆传媒. 鈥淚t starts early, and it is part of the way the disease actually happens.鈥�

TREM2 has been previously linked to other forms of dementia, and was first found by researchers with Iceland-based deCODE Genetics Inc., who mapped the genetic code of 2,200 people.

Other scientists searched for the gene variant in 3,550 Alzheimer鈥檚 patients and people suffering from other types of dementia, and found it was more common in those with Alzheimer鈥檚.

Study subjects who were found to have TREM2, but did not suffer from Alzheimer鈥檚, still had lower mental function than those without the gene variant.

Dr. Lili-Naz Hazrati, of the University Health network, is hopeful that studying TREM2 could lead to a major breakthrough in fighting the disease.

鈥淲e are finding different components of the disease and yes, we are very optimistic that we are going towards a treatment for Alzheimer鈥檚.鈥�

However, Dr. Rudolph Tanzi, a Harvard Medical School geneticist, was more cautious.

He told The Associated Press he would prefer to 鈥渟ee more evidence鈥� that TREM2 was linked to Alzheimer鈥檚 and not one of the other forms of dementia already connected to the gene variant.

With a report by CTV鈥檚 medical specialist Avis Favaro and producer Elizabeth St. Philip, and files from The Associated Press